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': 'The treatment of choice in fistula in ano \nSelect and explain. \nA. Anal dilatation, B. Fissurotomy, C. Fistulectomy, D. Fistulotomy', 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Fistulotomy", 'role': 'assistant'}]