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': 'High or low fistula in ano is termed according to its internal opening present with reference to \nSelect and explain. \nA. Anal canal, B. Dentate line, C. Anorectal ring, D. Sacral promontory', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e. Anorectal ring", 'role': 'assistant'}]