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: Pathology
First line treatment of trigeminal neuralgia is: 
Select and explain. 
A. Neurectomy., B. Carbamazepine., C. Regional nerve block., D. Radiofrequency.
B: Carbamazepine.
Answer: B: Carbamazepine. 
Explanation: None