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: Pharmacology
[{'content': 'Rizatriptan is a drug used for?(DNB 2012-section-1) \nSelect and explain. \nA. Prophylaxis of migraine, B. Acute migraine, C. Cluster headache, D. Chronc migraine', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. (b) Acute migraineRefiHarrison's 18/e, ch 14", 'role': 'assistant'}]