diff --git a/api/app/Exceptions/FormBuilder/InvalidOptionSpecException.php b/api/app/Exceptions/FormBuilder/InvalidOptionSpecException.php
new file mode 100644
index 00000000..c3b47280
--- /dev/null
+++ b/api/app/Exceptions/FormBuilder/InvalidOptionSpecException.php
@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Exceptions\FormBuilder;
+
+use RuntimeException;
+
+/**
+ * Raised by `FormFieldOptionService::replaceOptions()` (and the
+ * FormRequest validator in WS-5d commit 3) when a caller supplies an
+ * options spec list whose entries violate the row-shape contract:
+ * missing/oversized value or label, missing or non-int sort_order,
+ * malformed translations, duplicate values within the spec array, or
+ * any other shape failure documented on `assertSpecsValid`.
+ */
+final class InvalidOptionSpecException extends RuntimeException
+{
+}
diff --git a/api/app/Models/FormBuilder/FormField.php b/api/app/Models/FormBuilder/FormField.php
index eb2fd1c6..87fb1d3b 100644
--- a/api/app/Models/FormBuilder/FormField.php
+++ b/api/app/Models/FormBuilder/FormField.php
@@ -117,6 +117,12 @@ final class FormField extends Model
         return $this->morphMany(FormFieldConfig::class, 'owner');
     }
 
+    public function options(): MorphMany
+    {
+        return $this->morphMany(FormFieldOption::class, 'owner')
+            ->orderBy('sort_order');
+    }
+
     public function conditionalLogicGroups(): HasMany
     {
         return $this->hasMany(FormFieldConditionalLogicGroup::class, 'form_field_id');
diff --git a/api/app/Models/FormBuilder/FormFieldLibrary.php b/api/app/Models/FormBuilder/FormFieldLibrary.php
index 792c0895..d3ce490e 100644
--- a/api/app/Models/FormBuilder/FormFieldLibrary.php
+++ b/api/app/Models/FormBuilder/FormFieldLibrary.php
@@ -77,4 +77,10 @@ final class FormFieldLibrary extends Model
     {
         return $this->morphMany(FormFieldConfig::class, 'owner');
     }
+
+    public function options(): MorphMany
+    {
+        return $this->morphMany(FormFieldOption::class, 'owner')
+            ->orderBy('sort_order');
+    }
 }
diff --git a/api/app/Models/FormBuilder/FormFieldOption.php b/api/app/Models/FormBuilder/FormFieldOption.php
new file mode 100644
index 00000000..e7f29709
--- /dev/null
+++ b/api/app/Models/FormBuilder/FormFieldOption.php
@@ -0,0 +1,87 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models\FormBuilder;
+
+use App\Models\Scopes\FormFieldOptionScope;
+use Illuminate\Database\Eloquent\Concerns\HasUlids;
+use Illuminate\Database\Eloquent\Factories\HasFactory;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Relations\MorphTo;
+
+/**
+ * Relational home for RADIO / SELECT / MULTISELECT / CHECKBOX_LIST option
+ * rows. See ARCH-FORM-BUILDER §17.6 (WS-5d) and addendum Q3.
+ *
+ * Polymorphic owner (`form_field` / `form_field_library` aliases — reused
+ * from WS-5a). One row per (owner, value); duplicates are blocked by the
+ * `ffo_owner_value_unique` index and at the service level by
+ * `FormFieldOptionService::assertSpecsValid`. Per-locale translated labels
+ * live on the row in the `translations` JSON bag.
+ *
+ * @property string                       $id
+ * @property string                       $owner_type
+ * @property string                       $owner_id
+ * @property string                       $value
+ * @property string                       $label
+ * @property int                          $sort_order
+ * @property array<string, string>|null   $translations
+ * @property \Illuminate\Support\Carbon   $created_at
+ * @property \Illuminate\Support\Carbon   $updated_at
+ */
+final class FormFieldOption extends Model
+{
+    use HasFactory;
+    use HasUlids;
+
+    protected $table = 'form_field_options';
+
+    protected static function booted(): void
+    {
+        static::addGlobalScope(new FormFieldOptionScope());
+    }
+
+    protected $fillable = [
+        'owner_type',
+        'owner_id',
+        'value',
+        'label',
+        'sort_order',
+        'translations',
+    ];
+
+    /** @var array<string, string> */
+    protected $casts = [
+        'translations' => 'array',
+        'sort_order' => 'int',
+    ];
+
+    public function owner(): MorphTo
+    {
+        return $this->morphTo('owner', 'owner_type', 'owner_id');
+    }
+
+    /**
+     * Single source of truth for the per-row JSON shape consumed by
+     * snapshot writer, API resources, and activity-log diff
+     * reconstruction. Empty translations bag is omitted (preserves the
+     * current contract for monolingual schemas).
+     *
+     * @return array{value:string,label:string,sort_order:int,translations?:array<string,string>}
+     */
+    public function toJsonShape(): array
+    {
+        $shape = [
+            'value' => $this->value,
+            'label' => $this->label,
+            'sort_order' => $this->sort_order,
+        ];
+
+        if (is_array($this->translations) && $this->translations !== []) {
+            $shape['translations'] = $this->translations;
+        }
+
+        return $shape;
+    }
+}
diff --git a/api/app/Models/Scopes/FormFieldOptionScope.php b/api/app/Models/Scopes/FormFieldOptionScope.php
new file mode 100644
index 00000000..c7be15d4
--- /dev/null
+++ b/api/app/Models/Scopes/FormFieldOptionScope.php
@@ -0,0 +1,107 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Models\Scopes;
+
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormFieldLibrary;
+use App\Models\FormBuilder\FormSchema;
+use Illuminate\Database\Eloquent\Builder;
+use Illuminate\Database\Eloquent\Model;
+use Illuminate\Database\Eloquent\Scope;
+
+/**
+ * Fourth and final sibling in the form-field-child-table scope family,
+ * after `FormFieldBindingScope` (WS-5a),
+ * `FormFieldValidationRuleScope` and `FormFieldConfigScope` (WS-5b).
+ *
+ * Identical UNION-over-two-owner-chains shape:
+ *
+ *   owner_id ∈ (
+ *     SELECT id FROM form_fields
+ *       WHERE form_schema_id ∈ (SELECT id FROM form_schemas WHERE organisation_id = ?)
+ *     UNION
+ *     SELECT id FROM form_field_library
+ *       WHERE organisation_id = ?
+ *   )
+ *
+ * Now that all four concrete implementations exist, base-class
+ * extraction across the family is the logical follow-up — deferred to
+ * a separate work package per addendum §17.4.3 / §17.5.3 / §17.6.3.
+ *
+ * Escape hatch: `FormFieldOption::withoutGlobalScope(FormFieldOptionScope::class)`
+ * for cascade observers, backfill migrations, and platform super_admin
+ * paths.
+ */
+final class FormFieldOptionScope implements Scope
+{
+    public function __construct(
+        private readonly ?string $organisationId = null,
+    ) {}
+
+    public function apply(Builder $builder, Model $model): void
+    {
+        $orgId = $this->resolveOrganisationId();
+        if ($orgId === null) {
+            return;
+        }
+
+        $fieldIds = FormField::query()
+            ->withoutGlobalScope(OrganisationScope::class)
+            ->whereIn(
+                'form_schema_id',
+                FormSchema::query()
+                    ->withoutGlobalScope(OrganisationScope::class)
+                    ->where('organisation_id', $orgId)
+                    ->select('id'),
+            )
+            ->select('id');
+
+        $libraryIds = FormFieldLibrary::query()
+            ->withoutGlobalScope(OrganisationScope::class)
+            ->where('organisation_id', $orgId)
+            ->select('id');
+
+        $table = $model->getTable();
+
+        $builder->where(function (Builder $outer) use ($table, $fieldIds, $libraryIds): void {
+            $outer->where(function (Builder $q) use ($table, $fieldIds): void {
+                $q->where("$table.owner_type", 'form_field')
+                    ->whereIn("$table.owner_id", $fieldIds);
+            })->orWhere(function (Builder $q) use ($table, $libraryIds): void {
+                $q->where("$table.owner_type", 'form_field_library')
+                    ->whereIn("$table.owner_id", $libraryIds);
+            });
+        });
+    }
+
+    private function resolveOrganisationId(): ?string
+    {
+        if ($this->organisationId !== null) {
+            return $this->organisationId;
+        }
+
+        $route = request()->route();
+        if ($route === null) {
+            return null;
+        }
+
+        $org = $route->parameter('organisation');
+
+        if ($org instanceof \App\Models\Organisation) {
+            return $org->id;
+        }
+
+        if (is_string($org) && $org !== '') {
+            return $org;
+        }
+
+        $event = $route->parameter('event');
+        if ($event instanceof \App\Models\Event) {
+            return $event->organisation_id;
+        }
+
+        return null;
+    }
+}
diff --git a/api/app/Observers/FormBuilder/FormFieldChildTablesCascadeObserver.php b/api/app/Observers/FormBuilder/FormFieldChildTablesCascadeObserver.php
index 081d1774..6cc77df8 100644
--- a/api/app/Observers/FormBuilder/FormFieldChildTablesCascadeObserver.php
+++ b/api/app/Observers/FormBuilder/FormFieldChildTablesCascadeObserver.php
@@ -20,6 +20,7 @@ use Illuminate\Support\Facades\Schema;
  *                                                  per addendum Q3: library
  *                                                  is explicitly out of
  *                                                  scope for conditional_logic)
+ *   - `form_field_options`                        (WS-5d — both owner types)
  *
  * The conditions sibling table cascades automatically via the `group_id`
  * FK on the groups table — no direct entry here.
@@ -59,6 +60,13 @@ final class FormFieldChildTablesCascadeObserver
                 ->delete();
         }
 
+        if (Schema::hasTable('form_field_options')) {
+            DB::table('form_field_options')
+                ->where('owner_type', $ownerType)
+                ->where('owner_id', $ownerId)
+                ->delete();
+        }
+
         // Conditional-logic groups only apply to FormField (addendum Q3:
         // library mirror is out of scope). Condition rows cascade via
         // the group_id FK on the conditions table.
diff --git a/api/app/Services/FormBuilder/FormFieldOptionService.php b/api/app/Services/FormBuilder/FormFieldOptionService.php
new file mode 100644
index 00000000..e3cb8203
--- /dev/null
+++ b/api/app/Services/FormBuilder/FormFieldOptionService.php
@@ -0,0 +1,246 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Services\FormBuilder;
+
+use App\Exceptions\FormBuilder\InvalidOptionSpecException;
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormFieldLibrary;
+use App\Models\FormBuilder\FormFieldOption;
+use Illuminate\Support\Collection;
+use Illuminate\Support\Facades\DB;
+
+/**
+ * Owns all writes to `form_field_options`. Single source of truth for:
+ *
+ *   - row-shape enforcement (value/label/sort_order/translations)
+ *   - duplicate-value detection at the spec level (cleaner 422 than the
+ *     bare DB unique-constraint violation)
+ *   - library → field row-copy on insertFromLibrary (addendum Q3
+ *     row-copy mandate)
+ *   - serialisation into the rich-shape JSON consumed by snapshot
+ *     writer, API resources, and FilterRegistryController
+ *
+ * Pattern: one row per (owner, value). An empty specs array on
+ * `replaceOptions()` clears all option rows for the owner.
+ *
+ * Activity log convention — matches WS-5a / §17.4.2 / §17.5: emit
+ * `field.options_replaced` on the parent `FormField` only, not on
+ * `FormFieldLibrary`. Library-level audits live elsewhere.
+ *
+ * See ARCH-FORM-BUILDER §17.6 (WS-5d) for the broader rationale.
+ */
+final class FormFieldOptionService
+{
+    /**
+     * Locale shape: BCP-47 short form — `nl`, `en`, `nl_BE`, `en_GB`.
+     */
+    private const LOCALE_PATTERN = '/^[a-z]{2}(_[A-Z]{2})?$/';
+
+    /**
+     * Eager, ordered by `sort_order`. Scope-aware via the active
+     * organisation context.
+     *
+     * @return Collection<int, FormFieldOption>
+     */
+    public function optionsFor(FormField|FormFieldLibrary $owner): Collection
+    {
+        $type = $this->ownerTypeFor($owner);
+
+        return FormFieldOption::query()
+            ->where('owner_type', $type)
+            ->where('owner_id', $owner->getKey())
+            ->orderBy('sort_order')
+            ->get();
+    }
+
+    /**
+     * Replace the full option set on an owner transactionally. Validates
+     * every spec's shape (value / label / sort_order / translations /
+     * uniqueness) before any write lands.
+     *
+     * @param  list<array{value:string,label:string,sort_order:int,translations?:array<string,string>}>  $specs
+     * @return Collection<int, FormFieldOption>
+     */
+    public function replaceOptions(FormField|FormFieldLibrary $owner, array $specs): Collection
+    {
+        $this->assertSpecsValid($specs);
+
+        $ownerType = $this->ownerTypeFor($owner);
+
+        return DB::transaction(function () use ($owner, $ownerType, $specs): Collection {
+            FormFieldOption::query()
+                ->withoutGlobalScopes()
+                ->where('owner_type', $ownerType)
+                ->where('owner_id', $owner->getKey())
+                ->delete();
+
+            foreach ($specs as $spec) {
+                FormFieldOption::query()->withoutGlobalScopes()->create([
+                    'owner_type' => $ownerType,
+                    'owner_id' => $owner->getKey(),
+                    'value' => $spec['value'],
+                    'label' => $spec['label'],
+                    'sort_order' => $spec['sort_order'],
+                    'translations' => $this->normaliseTranslations($spec['translations'] ?? null),
+                ]);
+            }
+
+            $fresh = $this->optionsFor($owner);
+
+            if ($owner instanceof FormField) {
+                $owner->logFieldChange('field.options_replaced', [
+                    'options' => $this->toJsonShape($fresh),
+                ]);
+            }
+
+            return $fresh;
+        });
+    }
+
+    /**
+     * Row-copy from a library entry to a freshly-inserted field
+     * (addendum Q3 row-copy mandate). Every column is preserved; only
+     * `owner_type` / `owner_id` change. No activity-log emit — the
+     * wrapping library-insert emits its own field-creation event.
+     *
+     * @return Collection<int, FormFieldOption>
+     */
+    public function copyOptions(FormFieldLibrary|FormField $from, FormField|FormFieldLibrary $to): Collection
+    {
+        $rows = $this->optionsFor($from);
+
+        if ($rows->isEmpty()) {
+            return $rows;
+        }
+
+        $toType = $this->ownerTypeFor($to);
+
+        return DB::transaction(function () use ($rows, $to, $toType): Collection {
+            foreach ($rows as $row) {
+                FormFieldOption::query()->withoutGlobalScopes()->create([
+                    'owner_type' => $toType,
+                    'owner_id' => $to->getKey(),
+                    'value' => $row->value,
+                    'label' => $row->label,
+                    'sort_order' => $row->sort_order,
+                    'translations' => is_array($row->translations) && $row->translations !== []
+                        ? $row->translations
+                        : null,
+                ]);
+            }
+
+            return $this->optionsFor($to);
+        });
+    }
+
+    /**
+     * Serialise an option collection into the rich-shape array consumed
+     * by snapshot writer, API resources, and FilterRegistryController.
+     * Returns the mapped list (possibly empty); callers handle
+     * empty-collection → `null` emit at the resource boundary.
+     *
+     * @param  Collection<int, FormFieldOption>  $options
+     * @return list<array{value:string,label:string,sort_order:int,translations?:array<string,string>}>
+     */
+    public function toJsonShape(Collection $options): array
+    {
+        return $options
+            ->sortBy('sort_order')
+            ->values()
+            ->map(fn (FormFieldOption $option) => $option->toJsonShape())
+            ->all();
+    }
+
+    /**
+     * Public spec-shape gate — used by FormRequests (WS-5d commit 3) to
+     * reject malformed specs at the HTTP boundary before any write
+     * lands.
+     *
+     * @param  list<array<string, mixed>>  $specs
+     */
+    public function assertSpecsValid(array $specs): void
+    {
+        $seenValues = [];
+
+        foreach ($specs as $index => $spec) {
+            if (! is_array($spec)) {
+                throw new InvalidOptionSpecException(
+                    "Option spec at index {$index} must be an array.",
+                );
+            }
+
+            $value = $spec['value'] ?? null;
+            if (! is_string($value) || $value === '' || strlen($value) > 255) {
+                throw new InvalidOptionSpecException(
+                    "Option spec at index {$index}: 'value' is required, must be a non-empty string ≤255 chars.",
+                );
+            }
+
+            $label = $spec['label'] ?? null;
+            if (! is_string($label) || $label === '' || strlen($label) > 255) {
+                throw new InvalidOptionSpecException(
+                    "Option spec at index {$index}: 'label' is required, must be a non-empty string ≤255 chars.",
+                );
+            }
+
+            if (! array_key_exists('sort_order', $spec)
+                || ! is_int($spec['sort_order'])
+                || $spec['sort_order'] < 0) {
+                throw new InvalidOptionSpecException(
+                    "Option spec at index {$index}: 'sort_order' is required, must be a non-negative integer.",
+                );
+            }
+
+            if (array_key_exists('translations', $spec) && $spec['translations'] !== null) {
+                $translations = $spec['translations'];
+                if (! is_array($translations)) {
+                    throw new InvalidOptionSpecException(
+                        "Option spec at index {$index}: 'translations' must be an associative array of locale ⇒ string.",
+                    );
+                }
+                foreach ($translations as $locale => $translated) {
+                    if (! is_string($locale) || preg_match(self::LOCALE_PATTERN, $locale) !== 1) {
+                        throw new InvalidOptionSpecException(
+                            "Option spec at index {$index}: invalid locale key '{$locale}' (expected BCP-47 short form e.g. 'nl', 'en_GB').",
+                        );
+                    }
+                    if (! is_string($translated) || $translated === '' || strlen($translated) > 255) {
+                        throw new InvalidOptionSpecException(
+                            "Option spec at index {$index} locale '{$locale}': translated label must be a non-empty string ≤255 chars.",
+                        );
+                    }
+                }
+            }
+
+            if (in_array($value, $seenValues, true)) {
+                throw new InvalidOptionSpecException(
+                    "Option spec at index {$index}: duplicate value '{$value}' within the spec list.",
+                );
+            }
+            $seenValues[] = $value;
+        }
+    }
+
+    private function ownerTypeFor(FormField|FormFieldLibrary $owner): string
+    {
+        return $owner instanceof FormField ? 'form_field' : 'form_field_library';
+    }
+
+    /**
+     * Empty translation bags are stored as NULL — keeps query semantics
+     * clean and avoids whitespace differences between equivalent rows.
+     *
+     * @param  array<string, string>|null  $translations
+     * @return array<string, string>|null
+     */
+    private function normaliseTranslations(?array $translations): ?array
+    {
+        if ($translations === null || $translations === []) {
+            return null;
+        }
+
+        return $translations;
+    }
+}
diff --git a/api/database/factories/FormBuilder/FormFieldOptionFactory.php b/api/database/factories/FormBuilder/FormFieldOptionFactory.php
new file mode 100644
index 00000000..f60cf409
--- /dev/null
+++ b/api/database/factories/FormBuilder/FormFieldOptionFactory.php
@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Database\Factories\FormBuilder;
+
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormFieldLibrary;
+use App\Models\FormBuilder\FormFieldOption;
+use Illuminate\Database\Eloquent\Factories\Factory;
+
+/** @extends Factory<FormFieldOption> */
+final class FormFieldOptionFactory extends Factory
+{
+    protected $model = FormFieldOption::class;
+
+    /** @return array<string, mixed> */
+    public function definition(): array
+    {
+        $value = $this->faker->unique()->slug(2);
+
+        return [
+            'owner_type' => 'form_field',
+            'owner_id' => FormField::factory(),
+            'value' => $value,
+            'label' => ucfirst(str_replace('-', ' ', $value)),
+            'sort_order' => 0,
+            'translations' => null,
+        ];
+    }
+
+    public function forField(FormField $field): static
+    {
+        return $this->state(fn () => [
+            'owner_type' => 'form_field',
+            'owner_id' => $field->id,
+        ]);
+    }
+
+    public function forLibrary(FormFieldLibrary $library): static
+    {
+        return $this->state(fn () => [
+            'owner_type' => 'form_field_library',
+            'owner_id' => $library->id,
+        ]);
+    }
+
+    /**
+     * @param  list<string>  $locales
+     */
+    public function withTranslations(array $locales = ['en', 'de']): static
+    {
+        return $this->state(function (array $attributes) use ($locales) {
+            $base = (string) ($attributes['label'] ?? 'Option');
+            $bag = [];
+            foreach ($locales as $locale) {
+                $bag[$locale] = $base.' ('.$locale.')';
+            }
+
+            return ['translations' => $bag];
+        });
+    }
+}
diff --git a/api/database/migrations/2026_04_27_100000_create_form_field_options_table.php b/api/database/migrations/2026_04_27_100000_create_form_field_options_table.php
new file mode 100644
index 00000000..008a2e01
--- /dev/null
+++ b/api/database/migrations/2026_04_27_100000_create_form_field_options_table.php
@@ -0,0 +1,61 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * WS-5d commit 1 of 5 — fourth and final WS-5 sibling. Polymorphic
+ * morph-owned table for the RADIO / SELECT / MULTISELECT / CHECKBOX_LIST
+ * option rows, shared between form_fields and form_field_library via
+ * the `owner_type` discriminator (matches WS-5a / WS-5b morph alias
+ * registration in AppServiceProvider::registerMorphMap).
+ *
+ * Row shape:
+ *   - value        canonical storage value (string ≤255)
+ *   - label        default-locale display label (string ≤255)
+ *   - sort_order   stable order within owner (uint)
+ *   - translations { "<locale>": "<translated label>" } — JSON nullable
+ *
+ * UNIQUE(owner_type, owner_id, value) is the seed-bug guard: duplicate
+ * values per field have no semantic meaning and must fail at both the
+ * service-level (assertSpecsValid) and the DB-level. Index name
+ * `ffo_owner_value_unique` is a stable handle for future migrations.
+ *
+ * No soft delete — options are physical state, not audit. Submission
+ * snapshots carry the historical shape (matches §17.4 / §17.5 sibling
+ * convention). Cascade on owner delete is handled by
+ * FormFieldChildTablesCascadeObserver.
+ */
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::create('form_field_options', function (Blueprint $table) {
+            $table->ulid('id')->primary();
+            $table->string('owner_type', 40);
+            $table->ulid('owner_id');
+            $table->string('value', 255);
+            $table->string('label', 255);
+            $table->unsignedInteger('sort_order')->default(0);
+            $table->json('translations')->nullable();
+            $table->timestamps();
+
+            $table->index(
+                ['owner_type', 'owner_id', 'sort_order'],
+                'ffo_owner_sort_idx',
+            );
+            $table->unique(
+                ['owner_type', 'owner_id', 'value'],
+                'ffo_owner_value_unique',
+            );
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('form_field_options');
+    }
+};
diff --git a/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php b/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
index 9dfc41a5..4ecad6df 100644
--- a/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
+++ b/api/tests/Feature/FormBuilder/Bindings/FormFieldBindingMigrationTest.php
@@ -33,13 +33,14 @@ final class FormFieldBindingMigrationTest extends TestCase
 
     public function test_forward_migrations_backfill_rows_from_both_json_sources(): void
     {
-        // Roll back to pre-WS-5a state: 3 WS-5c migrations
-        // (backfill-conditional-logic, create-conditional-logic-conditions,
+        // Roll back to pre-WS-5a state: 1 WS-5d migration (create-options) +
+        // 4 WS-5c migrations (drop-conditional-logic-col,
+        // backfill-conditional-logic, create-conditional-logic-conditions,
         // create-conditional-logic-groups) + 5 WS-5b migrations
         // (drop-validation-cols, configs-backfill, create-configs,
         // validation-rules-backfill, create-validation-rules) +
-        // 2 WS-5a migrations (drop-binding-cols, create-bindings) = 10.
-        $this->artisan('migrate:rollback', ['--step' => 11])->assertSuccessful();
+        // 2 WS-5a migrations (drop-binding-cols, create-bindings) = 12.
+        $this->artisan('migrate:rollback', ['--step' => 12])->assertSuccessful();
         $this->assertFalse(Schema::hasTable('form_field_bindings'));
         $this->assertTrue(Schema::hasColumn('form_fields', 'binding'));
         $this->assertTrue(Schema::hasColumn('form_field_library', 'default_binding'));
@@ -100,8 +101,8 @@ final class FormFieldBindingMigrationTest extends TestCase
 
     public function test_rollback_reconstructs_json_and_drops_table(): void
     {
-        // Walk back the full WS-5c + WS-5b + WS-5a stack (10 migrations).
-        $this->artisan('migrate:rollback', ['--step' => 11])->assertSuccessful();
+        // Walk back the full WS-5d + WS-5c + WS-5b + WS-5a stack (12 migrations).
+        $this->artisan('migrate:rollback', ['--step' => 12])->assertSuccessful();
         [$fieldAId, , ] = $this->seedFieldsWithBindingJson();
         [$libAId, ] = $this->seedLibraryWithBindingJson();
 
@@ -111,11 +112,13 @@ final class FormFieldBindingMigrationTest extends TestCase
         $this->assertFalse(Schema::hasColumn('form_fields', 'binding'));
         $this->assertSame(5, DB::table('form_field_bindings')->count());
 
-        // Step back over WS-5c (3 migrations) + WS-5b (5 migrations) in one
-        // go → restores the pre-WS-5b state (conditional-logic,
-        // validation-rules and configs tables gone, validation_rules JSON
-        // columns reappear on source tables; binding contract intact).
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        // Step back over WS-5d (1 migration) + WS-5c (4 migrations) +
+        // WS-5b (5 migrations) in one go → restores the pre-WS-5b state
+        // (conditional-logic, validation-rules, configs and options tables
+        // gone, validation_rules JSON columns reappear on source tables;
+        // binding contract intact).
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
+        $this->assertFalse(Schema::hasTable('form_field_options'));
         $this->assertFalse(Schema::hasTable('form_field_conditional_logic_groups'));
         $this->assertFalse(Schema::hasTable('form_field_conditional_logic_conditions'));
         $this->assertFalse(Schema::hasTable('form_field_validation_rules'));
diff --git a/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
index 5483fd6a..716b1bed 100644
--- a/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
+++ b/api/tests/Feature/FormBuilder/ConditionalLogic/ConditionalLogicBackfillTest.php
@@ -31,8 +31,10 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_forward_backfill_builds_nested_tree_from_legacy_json(): void
     {
-        // Roll back only the backfill migration (latest WS-5c step).
-        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
+        // Roll back the WS-5d create-options + WS-5c drop-cl-col + WS-5c
+        // backfill-cl migrations to land in the conditional-logic JSON-era
+        // state with no relational form_field_options table yet.
+        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'conditional_logic'));
 
         $fieldId = $this->seedFieldWithJson([
@@ -153,7 +155,7 @@ final class ConditionalLogicBackfillTest extends TestCase
         ]);
 
         // Roll back only the backfill migration — writes the JSON back.
-        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
 
         $reconstructed = DB::table('form_fields')
             ->where('id', $fieldId)
@@ -180,7 +182,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_top_level_key_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'hide_when' => ['all' => [['field_slug' => 'x', 'operator' => 'equals', 'value' => 1]]],
@@ -193,7 +195,7 @@ final class ConditionalLogicBackfillTest extends TestCase
 
     public function test_unknown_comparison_operator_fails_migration(): void
     {
-        $this->artisan('migrate:rollback', ['--step' => 2])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 3])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'show_when' => ['all' => [['field_slug' => 'x', 'operator' => 'matches_regex', 'value' => 'y']]],
diff --git a/api/tests/Feature/FormBuilder/Options/FormFieldOptionServiceAndScopeTest.php b/api/tests/Feature/FormBuilder/Options/FormFieldOptionServiceAndScopeTest.php
new file mode 100644
index 00000000..3d05ebd0
--- /dev/null
+++ b/api/tests/Feature/FormBuilder/Options/FormFieldOptionServiceAndScopeTest.php
@@ -0,0 +1,442 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tests\Feature\FormBuilder\Options;
+
+use App\Exceptions\FormBuilder\InvalidOptionSpecException;
+use App\Models\FormBuilder\FormField;
+use App\Models\FormBuilder\FormFieldLibrary;
+use App\Models\FormBuilder\FormFieldOption;
+use App\Models\FormBuilder\FormSchema;
+use App\Models\Organisation;
+use App\Models\Scopes\FormFieldOptionScope;
+use App\Services\FormBuilder\FormFieldOptionService;
+use Illuminate\Database\QueryException;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Routing\Route;
+use Spatie\Activitylog\Models\Activity;
+use Tests\TestCase;
+
+/**
+ * Consolidated coverage for `form_field_options` — model relation,
+ * scope isolation, cascade, and service-layer contract (replace, copy,
+ * toJsonShape, assertSpecsValid). Mirrors the structure of the
+ * configs / validation-rules test suites (WS-5b).
+ */
+final class FormFieldOptionServiceAndScopeTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_field_morph_many_options_and_owner_morphto_roundtrip(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        FormFieldOption::factory()->forField($field)->create([
+            'value' => 'xs', 'label' => 'XS', 'sort_order' => 0,
+        ]);
+        FormFieldOption::factory()->forField($field)->create([
+            'value' => 'sm', 'label' => 'S', 'sort_order' => 1,
+        ]);
+
+        // Commit 1 coexistence: form_fields.options JSON cast still exists,
+        // so $field->options resolves to the array attribute rather than
+        // the morphMany. Explicit relation call until commit 3 drops the
+        // cast.
+        $options = $field->fresh()->options()->get();
+        $this->assertCount(2, $options);
+        $this->assertSame(['xs', 'sm'], $options->pluck('value')->all());
+        $this->assertSame(FormField::class, $options->first()->fresh()->owner::class);
+    }
+
+    public function test_library_morph_many_options_resolves(): void
+    {
+        $org = Organisation::factory()->create();
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        FormFieldOption::factory()->forLibrary($library)->create([
+            'value' => 'a', 'label' => 'A', 'sort_order' => 0,
+        ]);
+
+        $this->assertSame(
+            FormFieldLibrary::class,
+            $library->fresh()->options()->get()->first()->fresh()->owner::class,
+        );
+    }
+
+    public function test_to_json_shape_omits_empty_translations(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        $option = FormFieldOption::factory()->forField($field)->create([
+            'value' => 'a', 'label' => 'A', 'sort_order' => 0, 'translations' => null,
+        ]);
+
+        $this->assertSame(
+            ['value' => 'a', 'label' => 'A', 'sort_order' => 0],
+            $option->toJsonShape(),
+        );
+    }
+
+    public function test_to_json_shape_includes_translations(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        $option = FormFieldOption::factory()->forField($field)->create([
+            'value' => 'sm', 'label' => 'Small', 'sort_order' => 1,
+            'translations' => ['nl' => 'Klein', 'de' => 'Klein'],
+        ]);
+
+        $this->assertSame(
+            [
+                'value' => 'sm',
+                'label' => 'Small',
+                'sort_order' => 1,
+                'translations' => ['nl' => 'Klein', 'de' => 'Klein'],
+            ],
+            $option->toJsonShape(),
+        );
+    }
+
+    public function test_unique_constraint_blocks_duplicate_value_per_owner(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        FormFieldOption::factory()->forField($field)->create([
+            'value' => 'dup', 'label' => 'A', 'sort_order' => 0,
+        ]);
+
+        $this->expectException(QueryException::class);
+        FormFieldOption::factory()->forField($field)->create([
+            'value' => 'dup', 'label' => 'B', 'sort_order' => 1,
+        ]);
+    }
+
+    public function test_options_for_returns_options_in_sort_order(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        FormFieldOption::factory()->forField($field)->create(['value' => 'c', 'label' => 'C', 'sort_order' => 2]);
+        FormFieldOption::factory()->forField($field)->create(['value' => 'a', 'label' => 'A', 'sort_order' => 0]);
+        FormFieldOption::factory()->forField($field)->create(['value' => 'b', 'label' => 'B', 'sort_order' => 1]);
+
+        $options = app(FormFieldOptionService::class)->optionsFor($field);
+        $this->assertSame(['a', 'b', 'c'], $options->pluck('value')->all());
+    }
+
+    public function test_replace_options_creates_rows_transactionally(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        $service = app(FormFieldOptionService::class);
+        $service->replaceOptions($field, [
+            ['value' => 'red', 'label' => 'Red', 'sort_order' => 0],
+            ['value' => 'green', 'label' => 'Green', 'sort_order' => 1],
+        ]);
+
+        $this->assertSame(['red', 'green'], $service->optionsFor($field)->pluck('value')->all());
+    }
+
+    public function test_replace_options_invalid_specs_roll_back_no_partial_state(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        $service = app(FormFieldOptionService::class);
+        $service->replaceOptions($field, [
+            ['value' => 'old', 'label' => 'Old', 'sort_order' => 0],
+        ]);
+
+        try {
+            $service->replaceOptions($field, [
+                ['value' => 'new1', 'label' => 'New 1', 'sort_order' => 0],
+                ['value' => '', 'label' => 'bad', 'sort_order' => 1],
+            ]);
+            $this->fail('Expected InvalidOptionSpecException.');
+        } catch (InvalidOptionSpecException) {
+            // expected
+        }
+
+        $this->assertSame(['old'], $service->optionsFor($field)->pluck('value')->all());
+    }
+
+    public function test_replace_options_emits_activity_log_on_field_only(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        $service = app(FormFieldOptionService::class);
+
+        $service->replaceOptions($field, [
+            ['value' => 'a', 'label' => 'A', 'sort_order' => 0],
+        ]);
+        $service->replaceOptions($library, [
+            ['value' => 'b', 'label' => 'B', 'sort_order' => 0],
+        ]);
+
+        $fieldEvent = Activity::query()
+            ->where('subject_type', 'form_field')
+            ->where('subject_id', $field->id)
+            ->where('description', 'field.options_replaced')
+            ->first();
+        $this->assertNotNull($fieldEvent);
+        $this->assertSame(
+            [['value' => 'a', 'label' => 'A', 'sort_order' => 0]],
+            $fieldEvent->properties->get('options'),
+        );
+
+        $this->assertNull(Activity::query()
+            ->where('subject_type', 'form_field_library')
+            ->where('description', 'field.options_replaced')
+            ->first());
+    }
+
+    public function test_copy_options_clones_every_row_including_translations_and_sort_order(): void
+    {
+        $org = Organisation::factory()->create();
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        FormFieldOption::factory()->forLibrary($library)->create([
+            'value' => 'one', 'label' => 'One', 'sort_order' => 1,
+            'translations' => ['nl' => 'Een'],
+        ]);
+        FormFieldOption::factory()->forLibrary($library)->create([
+            'value' => 'two', 'label' => 'Two', 'sort_order' => 0,
+            'translations' => null,
+        ]);
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        app(FormFieldOptionService::class)->copyOptions($library, $field);
+
+        $copied = app(FormFieldOptionService::class)->optionsFor($field);
+        $this->assertCount(2, $copied);
+        $this->assertSame(['two', 'one'], $copied->pluck('value')->all());
+        $this->assertSame(['nl' => 'Een'], $copied->firstWhere('value', 'one')->translations);
+        $this->assertNull($copied->firstWhere('value', 'two')->translations);
+    }
+
+    public function test_copy_options_emits_no_activity_log(): void
+    {
+        $org = Organisation::factory()->create();
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        FormFieldOption::factory()->forLibrary($library)->create(['value' => 'a', 'label' => 'A', 'sort_order' => 0]);
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        app(FormFieldOptionService::class)->copyOptions($library, $field);
+
+        $this->assertNull(Activity::query()
+            ->where('description', 'field.options_replaced')
+            ->first());
+    }
+
+    public function test_to_json_shape_byte_equal_to_contract(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+
+        $service = app(FormFieldOptionService::class);
+        $service->replaceOptions($field, [
+            ['value' => 'red', 'label' => 'Red', 'sort_order' => 0],
+            ['value' => 'green', 'label' => 'Green', 'sort_order' => 1, 'translations' => ['nl' => 'Groen']],
+        ]);
+
+        $shape = $service->toJsonShape($service->optionsFor($field));
+        $this->assertSame(
+            [
+                ['value' => 'red', 'label' => 'Red', 'sort_order' => 0],
+                ['value' => 'green', 'label' => 'Green', 'sort_order' => 1, 'translations' => ['nl' => 'Groen']],
+            ],
+            $shape,
+        );
+    }
+
+    public function test_assert_specs_valid_rejects_non_array_spec(): void
+    {
+        $this->expectException(InvalidOptionSpecException::class);
+        app(FormFieldOptionService::class)->assertSpecsValid(['not-an-array']);
+    }
+
+    public function test_assert_specs_valid_rejects_missing_or_oversized_value(): void
+    {
+        $service = app(FormFieldOptionService::class);
+
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['label' => 'L', 'sort_order' => 0],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => '', 'label' => 'L', 'sort_order' => 0],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => str_repeat('x', 256), 'label' => 'L', 'sort_order' => 0],
+        ]));
+    }
+
+    public function test_assert_specs_valid_rejects_missing_or_oversized_label(): void
+    {
+        $service = app(FormFieldOptionService::class);
+
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'sort_order' => 0],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => '', 'sort_order' => 0],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => str_repeat('y', 256), 'sort_order' => 0],
+        ]));
+    }
+
+    public function test_assert_specs_valid_rejects_bad_sort_order(): void
+    {
+        $service = app(FormFieldOptionService::class);
+
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L'],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => '0'],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => -1],
+        ]));
+    }
+
+    public function test_assert_specs_valid_rejects_translations_not_array(): void
+    {
+        $this->expectException(InvalidOptionSpecException::class);
+        app(FormFieldOptionService::class)->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => 0, 'translations' => 'not-array'],
+        ]);
+    }
+
+    public function test_assert_specs_valid_rejects_invalid_locale_key(): void
+    {
+        $this->expectException(InvalidOptionSpecException::class);
+        app(FormFieldOptionService::class)->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => 0, 'translations' => ['XX' => 'bad']],
+        ]);
+    }
+
+    public function test_assert_specs_valid_rejects_invalid_translated_value(): void
+    {
+        $service = app(FormFieldOptionService::class);
+
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => 0, 'translations' => ['nl' => '']],
+        ]));
+        $this->assertThrowsInvalidSpec(fn () => $service->assertSpecsValid([
+            ['value' => 'v', 'label' => 'L', 'sort_order' => 0, 'translations' => ['nl' => str_repeat('a', 256)]],
+        ]));
+    }
+
+    public function test_assert_specs_valid_rejects_duplicate_values(): void
+    {
+        $this->expectException(InvalidOptionSpecException::class);
+        app(FormFieldOptionService::class)->assertSpecsValid([
+            ['value' => 'dup', 'label' => 'A', 'sort_order' => 0],
+            ['value' => 'dup', 'label' => 'B', 'sort_order' => 1],
+        ]);
+    }
+
+    public function test_scope_isolates_options_per_organisation_both_owner_types(): void
+    {
+        [$orgA, $fieldA, $libraryA] = $this->seedOrgWithOptions();
+        [$orgB, $fieldB, $libraryB] = $this->seedOrgWithOptions();
+
+        $this->withOrgRoute($orgA);
+        $ids = FormFieldOption::query()->pluck('owner_id')->sort()->values()->all();
+        $expected = collect([$fieldA->id, $libraryA->id])->sort()->values()->all();
+        $this->assertSame($expected, $ids);
+
+        // Escape hatch.
+        $this->assertSame(
+            4,
+            FormFieldOption::query()->withoutGlobalScope(FormFieldOptionScope::class)->count(),
+        );
+        $this->assertSame(2, FormFieldOption::query()->count());
+    }
+
+    public function test_cascade_options_deleted_on_field_soft_delete(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        FormFieldOption::factory()->forField($field)->create(['value' => 'a', 'label' => 'A']);
+
+        $this->assertSame(1, FormFieldOption::query()->withoutGlobalScopes()
+            ->where('owner_id', $field->id)->count());
+
+        $field->delete(); // soft delete on FormField
+        $this->assertSame(0, FormFieldOption::query()->withoutGlobalScopes()
+            ->where('owner_id', $field->id)->count());
+    }
+
+    public function test_cascade_options_deleted_on_field_force_delete(): void
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        FormFieldOption::factory()->forField($field)->create(['value' => 'a', 'label' => 'A']);
+
+        $field->forceDelete();
+        $this->assertSame(0, FormFieldOption::query()->withoutGlobalScopes()
+            ->where('owner_id', $field->id)->count());
+    }
+
+    public function test_cascade_options_deleted_on_library_delete(): void
+    {
+        $org = Organisation::factory()->create();
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        FormFieldOption::factory()->forLibrary($library)->create(['value' => 'a', 'label' => 'A']);
+
+        $library->delete();
+        $this->assertSame(0, FormFieldOption::query()->withoutGlobalScopes()
+            ->where('owner_id', $library->id)->count());
+    }
+
+    /** @return array{0:Organisation,1:FormField,2:FormFieldLibrary} */
+    private function seedOrgWithOptions(): array
+    {
+        $org = Organisation::factory()->create();
+        $schema = FormSchema::factory()->create(['organisation_id' => $org->id]);
+        $field = FormField::factory()->create(['form_schema_id' => $schema->id]);
+        $library = FormFieldLibrary::factory()->create(['organisation_id' => $org->id]);
+        FormFieldOption::factory()->forField($field)->create(['value' => 'fld-'.$field->id, 'label' => 'F']);
+        FormFieldOption::factory()->forLibrary($library)->create(['value' => 'lib-'.$library->id, 'label' => 'L']);
+
+        return [$org, $field, $library];
+    }
+
+    private function withOrgRoute(Organisation $org): void
+    {
+        $route = new Route(['GET'], '/_test', static fn () => null);
+        $route->bind(request());
+        $route->setParameter('organisation', $org);
+        request()->setRouteResolver(static fn () => $route);
+    }
+
+    private function assertThrowsInvalidSpec(callable $fn): void
+    {
+        try {
+            $fn();
+        } catch (InvalidOptionSpecException) {
+            $this->assertTrue(true);
+
+            return;
+        }
+        $this->fail('Expected InvalidOptionSpecException, none thrown.');
+    }
+}
diff --git a/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php b/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
index 750a5c4b..ade2dd44 100644
--- a/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
+++ b/api/tests/Feature/FormBuilder/ValidationRules/FormFieldValidationRuleBackfillTest.php
@@ -31,13 +31,15 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
 
     public function test_forward_migration_backfills_rows_with_field_type_dispatch(): void
     {
-        // Roll back: 2 WS-5c migrations (create-conditional-logic-conditions,
+        // Roll back: 1 WS-5d migration (create-options) +
+        // 4 WS-5c migrations (drop-conditional-logic-col,
+        // backfill-conditional-logic, create-conditional-logic-conditions,
         // create-conditional-logic-groups) + 5 WS-5b migrations
         // (drop-cols + configs-backfill + create-configs +
-        // validation-rules-backfill + create-validation-rules) = 7.
+        // validation-rules-backfill + create-validation-rules) = 10.
         // Brings us to the pre-WS-5b state: validation_rules JSON column
-        // present, no relational tables for WS-5b.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        // present, no relational tables for WS-5b/c/d.
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
         $this->assertFalse(Schema::hasTable('form_field_validation_rules'));
         $this->assertTrue(Schema::hasColumn('form_fields', 'validation_rules'));
 
@@ -98,7 +100,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
 
         $fieldId = $this->seedFieldWithJson([
             'field_type' => 'TAG_PICKER',
@@ -122,7 +124,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
 
         $fieldId = $this->seedFieldWithJson([
             'field_type' => 'TEXT',
@@ -149,7 +151,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'field_type' => 'TEXT',
@@ -166,7 +168,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // (validation_rules JSON column present; no relational tables for
         // WS-5b). Step count: drop-cols + configs-backfill + create-configs
         // + validation-rules-backfill + create-validation-rules = 5.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
 
         $this->seedFieldWithJson([
             'field_type' => 'BOOLEAN',
@@ -185,7 +187,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
         // full-back-then-full-forward cycle — rolling back all WS-5b
         // migrations restores the pre-WS-5b state (columns present on
         // source tables; validation rules relational table gone).
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
         [$numberId] = $this->seedFields();
 
         $this->artisan('migrate')->assertSuccessful();
@@ -200,7 +202,7 @@ final class FormFieldValidationRuleBackfillTest extends TestCase
 
         // Roll back WS-5b fully → column reappears and carries canonical JSON
         // reconstructed from the relational rows.
-        $this->artisan('migrate:rollback', ['--step' => 9])->assertSuccessful();
+        $this->artisan('migrate:rollback', ['--step' => 10])->assertSuccessful();
         $this->assertTrue(Schema::hasColumn('form_fields', 'validation_rules'));
 
         $field = DB::table('form_fields')->where('id', $numberId)->first();