This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.N.S, Subject name: Medicine
[{'content': 'Which of the following drug is used for prophylaxis of migraine? \nSelect and explain. \nA. Diclofenac, B. Flunarizine, C. Sumatriptan, D. Dihydroergotamine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Drugs used in prophylaxis of migraine Propranolol/other beta blockers Amitriptyline/other tricyclic antidepressants Fluanarazine/other Ca2+ channel blockers Valproate/topiramate Methysergide/cyproheptadine Ref: KD Tripathi, Pg 169', 'role': 'assistant'}]