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: Pathology
[{'content': 'Bilateral contracted kidney occurs in all except \nSelect and explain. \nA. Diabetes mellitus, B. Benign nephrosclerosis, C. Chronic pyelonephritis, D. Chronic glomerular nephritis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]