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
On chronic treatment with a drug, a patient presents with gingival hyperplasia and facial hirsutism. The drug most likely to cause these side effects is : 
Select and explain. 
A. Phenytoin, B. Carbamazepine, C. Valproic acid, D. Phenobarbitone
A: Phenytoin
Answer: A: Phenytoin 
Explanation: None