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
Which is the first line of treatment for overactive bladder? 
Select and explain. 
A. Antimuscarinic drug, B. Behavioural therapy, C. Cholinergic drug, D. Botulinum toxin type A
B: Behavioural therapy
Answer: B: Behavioural therapy 
Explanation: Behavioural therapy includes bladder training, pelvic floor exercise, fluid management.