This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pharmacology
[{'content': 'Recently approved drug for migraine prophylaxis is: \nSelect and explain. \nA. Sumatriptan, B. Topiramate, C. Gabapentin, D. Propranolol', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Topiramate has been approved for prophylaxis of migraine;\xa0may\xa0be\xa0used\xa0when\xa0blockers/other\xa0prophylactics\xa0are\xa0contraindicated\xa0or\xa0are not\xa0effective.', 'role': 'assistant'}]