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': 'Causes of acute retention of urine include all/except: \nSelect and explain. \nA. Meatal ulcer with scabbing in children, B. Haemorrhoidectomy, C. Herniorraphy, D. Fecal impaction', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]