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: Radiology
[{'content': 'In intravenous pyelography, one contracted kidney indicates: \nSelect and explain. \nA. Hydronephrosis, B. Polycystic kidney, C. Chronic glomerulonephritis, D. Chronic pyelonephritis', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. Chronic pyelonephritis', 'role': 'assistant'}]