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': 'Prophylactic maintenance serum level of lihium is \nSelect and explain. \nA. 0.2 - 0.8 meq/L, B. 0.7 -1.2 meq/L, C. 1.2 - 2.0 meq/L, D. 1.2 - 2.0 meq/L', 'role': 'user'}, {'content': 'Answer: B \nExplanation: B i.e. 0.7 - 1.2 meq/L', 'role': 'assistant'}]