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
NOT a cause of granular contracted kidney - 
Select and explain. 
A. Diabetes mellitus, B. Chronic pyelonephritis, C. Benign nephrosclerosis, D. Chronic glomerulonephritis
A: Diabetes mellitus
Answer: A: Diabetes mellitus 
Explanation: None