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: Gynaecology & Obstetrics
[{'content': "Commonest cause of recto vaginal fistula is : \nSelect and explain. \nA. Following Weheim's operation, B. Pressure necrosis during labour, C. Improper repair of perineal tear, D. Abnormal presentation", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Improper repair of perineal tear', 'role': 'assistant'}]