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: Medicine
[{'content': 'What is drug of choice for acute attack of migraine \nSelect and explain. \nA. Methysergide, B. Caffeine, C. Amitryptiline, D. Sumatriptan', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Answer is D (Sumatriptan): The drug of choice for an acute attack of migraine is Sumatriptan.', 'role': 'assistant'}]