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': 'Five-day self subsiding pain is diagnostic of ? \nSelect and explain. \nA. Anal fissure, B. Fi stul -in -ano, C. Thrombosed external hemorrhoids, D. Thrombosed internal hemorrhoids', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Thrombosed external hemorrhoids", 'role': 'assistant'}]