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: Psychiatry
[{'content': 'DOC for rapid cycling MDP - \nSelect and explain. \nA. Lithium, B. Valproate, C. Calcium channel blocker, D. Carbamazepine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: DOC for rapid cyclers is Valproate. \nAlternatives are Lithium, Carbamazepine and Lamotrigine.', 'role': 'assistant'}]