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': 'NOT a cause of granular contracted kidney - \nSelect and explain. \nA. Diabetes mellitus, B. Chronic pyelonephritis, C. Benign nephrosclerosis, D. Chronic glomerulonephritis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]