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': 'Lithium is treatment of choice for \nSelect and explain. \nA. Unipolar MDP prophylaxis, B. Bipolar MDP prophylaxis, C. Schizophrenia, D. Acute mania', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. Bipolar MDP prophylaxis', 'role': 'assistant'}]