diff --git a/src/lib/testService.js b/src/lib/testService.js
index 35a8965..0bd3d0f 100644
--- a/src/lib/testService.js
+++ b/src/lib/testService.js
@@ -38,7 +38,7 @@ function dominantCorrectIndex(questions) {
   const counts = [0, 0, 0, 0];
   for (const q of questions) counts[q.correctIndex] = (counts[q.correctIndex] || 0) + 1;
   const max = Math.max(...counts);
-  return max / questions.length > 0.5 ? { index: counts.indexOf(max), ratio: max / questions.length } : null;
+  return max / questions.length > 0.8 ? { index: counts.indexOf(max), ratio: max / questions.length } : null;
 }
 
 function validateBatchQuality(questions) {
@@ -66,7 +66,7 @@ Topic: ${topic.label}
 Type: ${topic.type}
 Description: ${topic.description}
 
-Options must be prefixed "A) ", "B) ", "C) ", "D) ". Make questions specific and practical, not trivial. Example: a question whose correct answer is option C uses "correctIndex": 2.`;
+Options must be prefixed "A) ", "B) ", "C) ", "D) ". Make questions specific and practical, not trivial. Ensure correct answers are evenly distributed.`;
 
   const result = await callLLM({
     task: 'quiz.generate',