This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Surgery
[{'content': 'Which of the following is least useful in Rx of "Overactive bladder"? \nSelect and explain. \nA. Oxybutynin, B. Tolterodine, C. Duloxetine, D. Darifenacin', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Duloxitin is use in the treatment of stress incontinence.', 'role': 'assistant'}]