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: Pharmacology
Drug of choice for prophylaxis of mania is ? 
Select and explain. 
A. Lithium, B. Haloperidol, C. Clozapine, D. Carbamazepine
A: Lithium
Answer: A: Lithium 
Explanation: Ans. is 'a' i.e., Lithium