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
The drug of choice for a patient with a combination of primary generalized tonic clonic seizure and absence seizures is: 
Select and explain. 
A. Ethosuximide, B. Carbamazepine, C. Valproic acid, D. Phenytoin sodium
C: Valproic acid
Answer: C: Valproic acid 
Explanation: None