This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Autonomic nervous system, Subject name: Pharmacology
[{'content': 'Which of the following drug is used for overactive bladder? \nSelect and explain. \nA. Duloxetine, B. Darifenacin, C. Oxybutynin, D. Flavoxate', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Ref:KD Tripathi pharmacology 7th edition (page.no: 118) Darifenacin & Solifenacin are competitive muscarinic receptor antagonists of the M3 muscarinic receptor of the bladder. Receptor blocking limits bladder contractions, and reduce symptoms of bladder irritability/overactivity', 'role': 'assistant'}]