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
[{'content': 'Which is the first line of treatment for overactive bladder? \nSelect and explain. \nA. Antimuscarinic drug, B. Behavioural therapy, C. Cholinergic drug, D. Botulinum toxin type A', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Behavioural therapy includes bladder training, pelvic floor exercise, fluid management.', 'role': 'assistant'}]