diff --git a/frontend/src/components/content/InteractivePracticeBlock.tsx b/frontend/src/components/content/InteractivePracticeBlock.tsx
index ffaefc2..9a3be54 100644
--- a/frontend/src/components/content/InteractivePracticeBlock.tsx
+++ b/frontend/src/components/content/InteractivePracticeBlock.tsx
@@ -1,5 +1,5 @@
 import { useRef, useState } from 'react'
-import { CheckCircle2, Circle, ArrowRight } from 'lucide-react'
+import { CheckCircle2, Circle, XCircle, ArrowRight } from 'lucide-react'
 
 import { Button } from '@/components/ui/button'
 import { Textarea } from '@/components/ui/textarea'
@@ -26,6 +26,7 @@ export function InteractivePracticeBlock({
   const interaction = block.interaction
   const startedAt = useRef<number | null>(null)
   const [selectedOptionId, setSelectedOptionId] = useState<string | null>(null)
+  const [submitted, setSubmitted] = useState(false)
   const [responseText, setResponseText] = useState('')
 
   if (interaction?.type !== 'multiple_choice') {
@@ -47,11 +48,14 @@ export function InteractivePracticeBlock({
         <p className="text-base font-medium leading-7 text-slate-900">{interaction.prompt}</p>
         {interaction.options.map((option) => {
           const selected = option.option_id === selectedOptionId
+          const isCorrectOption = option.option_id === interaction.correct_option_id
+          const showCorrect = submitted && isCorrectOption
+          const showIncorrect = submitted && selected && !isCorrectOption
           return (
             <button
               key={option.option_id}
               type="button"
-              disabled={disabled}
+              disabled={disabled || submitted}
               onClick={() => {
                 if (startedAt.current === null) {
                   startedAt.current = Date.now()
@@ -60,23 +64,33 @@ export function InteractivePracticeBlock({
               }}
               className={[
                 'w-full rounded-xl border px-4 py-4 text-left transition-colors',
-                selected
+                showCorrect
                   ? 'border-emerald-500 bg-emerald-50 shadow-sm'
-                  : 'border-slate-200 bg-slate-50 hover:border-slate-300 hover:bg-white',
-                disabled ? 'cursor-not-allowed opacity-70' : '',
+                  : showIncorrect
+                    ? 'border-red-400 bg-red-50 shadow-sm'
+                    : selected
+                      ? 'border-emerald-500 bg-emerald-50 shadow-sm'
+                      : 'border-slate-200 bg-slate-50 hover:border-slate-300 hover:bg-white',
+                disabled || submitted ? 'cursor-not-allowed opacity-70' : '',
               ].join(' ')}
             >
               <div className="flex items-start gap-3">
-                {selected ? (
+                {showCorrect ? (
+                  <CheckCircle2 className="mt-0.5 h-5 w-5 shrink-0 text-emerald-600" />
+                ) : showIncorrect ? (
+                  <XCircle className="mt-0.5 h-5 w-5 shrink-0 text-red-500" />
+                ) : selected ? (
                   <CheckCircle2 className="mt-0.5 h-5 w-5 shrink-0 text-emerald-600" />
                 ) : (
                   <Circle className="mt-0.5 h-5 w-5 shrink-0 text-slate-400" />
                 )}
                 <div className="space-y-1">
                   <p className="text-sm font-semibold text-slate-900">{option.label}</p>
-                  <p className="whitespace-pre-line text-sm leading-6 text-slate-700">
-                    {option.body}
-                  </p>
+                  {submitted && option.body && (
+                    <p className="whitespace-pre-line text-sm leading-6 text-slate-700">
+                      {option.body}
+                    </p>
+                  )}
                 </div>
               </div>
             </button>
@@ -107,6 +121,7 @@ export function InteractivePracticeBlock({
           if (!selectedOptionId) {
             return
           }
+          setSubmitted(true)
           onSubmit({
             blockId: block.block_id ?? block.title,
             selectedOptionId,
diff --git a/src/dibble/services/llm_prompting.py b/src/dibble/services/llm_prompting.py
index cdc8cdb..f1e4aae 100644
--- a/src/dibble/services/llm_prompting.py
+++ b/src/dibble/services/llm_prompting.py
@@ -277,13 +277,17 @@ def _block_schema_contract(content_type: RequestedContentType) -> str:
             '{"kind":"summary","title":"...","body":"..."},'
             '{"kind":"practice_problem","title":"...","body":"...",'
             '"interaction":{"type":"multiple_choice","prompt":"...","options":['
-            '{"option_id":"A","label":"Option A","body":"..."},'
-            '{"option_id":"B","label":"Option B","body":"..."}],'
+            '{"option_id":"A","label":"Option A","body":"why a student might pick this"},'
+            '{"option_id":"B","label":"Option B","body":"why a student might pick this"}],'
             '"correct_option_id":"B",'
             '"reveal":{"trigger":"after_selection","prompt":"...","support":"...","placeholder":"..."}}}'
             ']}. Always include at least one summary block and one practice_problem block. '
             "For the practice_problem block, put the learner's actual choice set in interaction.options, "
-            "keep body to a short cue, and use plain text only."
+            "keep body to a short cue, and use plain text only. "
+            "CRITICAL: option body must NEVER reveal whether the option is correct or incorrect. "
+            "Do not use words like 'Correct', 'Right', 'Wrong', or 'Incorrect' in option body. "
+            "Option body should describe the reasoning or common misconception behind the choice, "
+            "not whether it is the right answer. Correctness feedback is shown separately after submission."
         )
     return (
         '{"blocks":[{"kind":"summary","title":"...","body":"..."},{"kind":"instruction","title":"...","body":"..."}]}. '
@@ -296,11 +300,12 @@ def _stream_schema_contract(content_type: RequestedContentType) -> str:
         return (
             '{"block_index":0,"block":{"kind":"practice_problem","title":"...","body":"...",'
             '"interaction":{"type":"multiple_choice","prompt":"...","options":['
-            '{"option_id":"A","label":"Option A","body":"..."},'
-            '{"option_id":"B","label":"Option B","body":"..."}],'
+            '{"option_id":"A","label":"Option A","body":"why a student might pick this"},'
+            '{"option_id":"B","label":"Option B","body":"why a student might pick this"}],'
             '"correct_option_id":"B",'
             '"reveal":{"trigger":"after_selection","prompt":"...","support":"...","placeholder":"..."}}},"done":true}. '
-            "Emit one complete block object per line for interactive practice blocks."
+            "Emit one complete block object per line for interactive practice blocks. "
+            "Option body must NEVER reveal whether the option is correct or incorrect."
         )
     return (
         '{"block_index":0,"kind":"summary","title":"...","body_delta":"...","done":true}. '