This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pharmacology
Which of the following factors markedly increases the risk of valproate-induced liver toxicity? 
Select and explain. 
A. Male gender, B. Age younger than 2 year, C. Family history of epilepsy, D. Allergic reactions to phenobarbital
B: Age younger than 2 year
Answer: B: Age younger than 2 year 
Explanation: .