This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Urology, Subject name: Surgery
[{'content': 'Obstructive causes of acute renal failure are all Except \nSelect and explain. \nA. Bilharzia, B. Duplex ureter, C. Retroperitoneal fibrosis, D. Renal calculi', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Obstructive causes of acute renal failure include:* calculi;* pelvic malignancy;* surgery;* retroperitoneal fibrosis;* bilharzia;* crystalluria.Bailey and love 26e pg: 1284', 'role': 'assistant'}]