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: Medicine
A 4-month pregnant lady on treatment with valproate regularly asked for your advice regarding taking the drug during pregnancy. What is the best course of action - 
Select and explain. 
A. Immediately tape off valproate and start lamotrigine, B. Change to carbamazepine, C. Continue valproate and monitor blood levels, D. Slowly tape dose of valproate
C: Continue valproate and monitor blood levels
Answer: C: Continue valproate and monitor blood levels 
Explanation: None