fixed typo

app/routes.py

@@ -1225,7 +1225,7 @@ def attemptFormative(id):
                         test_attempt_id=new_attempt.id,
                         mcq_id=qid,
                         fib_id=None,
-                        student_answer=mcq[user_letter]
+                        student_answer=user_letter
                         )
                         db.session.add(attempt)
                         db.session.commit()