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 mechanism of action of valproic acid is 
Select and explain. 
A. Inhibition of Na+ channel inactivation, B. Inhibition of GABA, C. Opening of K+ channels, D. Inhibition of 'T' type Ca+2 current
D: Inhibition of 'T' type Ca+2 current
Answer: D: Inhibition of 'T' type Ca+2 current 
Explanation: None