This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Anatomy
[{'content': 'Which of the following drugs is used for the prophylaxis of migraine but not for agina pectoris \nSelect and explain. \nA. Verapamil, B. Diltiazem, C. Flunarizine, D. Amlodipine', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ref-KDT 6/e p172', 'role': 'assistant'}]