A patient had several seizures when she was a young child. She is now 13 years old and has been seizure-free for at least 5 years while taking carbamazepine. Choose the correct statement:
a. Should be discontinued immediately and substituted with topiramate
b. Should be tapered gradually to minimize the risk of seizures
c. Switch to phenytoin for better efficacy
d. Increase the dosage for better seizure control