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: Surgery
[{'content': 'Surgery for fissure in ano is \nSelect and explain. \nA. Seton’s procedure, B. Lateral spincterectomy, C. Well’s procedure, D. Winter’s procedure', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Lateral spincterectomy is done for pts of fissure in ano whom medical treatment fails.', 'role': 'assistant'}]