This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Central Nervous system, Subject name: Pharmacology
Weight gain is not seen with: 
Select and explain. 
A. Chlorpromazine, B. Sodium valproate, C. Carbamazepine, D. Phentermine
D: Phentermine
Answer: D: Phentermine 
Explanation: Ref:CMDT 2010/1137 Phentermine was used for treatment of obesity. It decreases appetite and causes weight loss.