This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidney and ureter, Subject name: Surgery
[{'content': 'Most common predisposing factor for chronic pyelonephritis is: \nSelect and explain. \nA. Diabetes mellitus, B. Renal stone, C. Posterior urethral valve, D. Vesicoureteric reflux', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Chronic pyelonephritis is so often associated with vesicoureteric reflux that some feel that it is better named "Reflux nephropathy". It is impoant cause of renal damage and death from end - stage renal failure.', 'role': 'assistant'}]