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 rapid cyclers in manic-depressive psychosis is - 
Select and explain. 
A. Carbamazepine, B. Valproate, C. Phenytoin, D. Lithium
B: Valproate
Answer: B: Valproate 
Explanation: Ans. is 'b' i.e., Valproate o Valproate is paicularly useful for rapid cyclers.