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: Medicine
Most common cause of chronic kidney disease 
Select and explain. 
A. Diabetes mellitus, B. Hypertension, C. PCKD, D. Hepatorenal Syndrome
A: Diabetes mellitus
Answer: A: Diabetes mellitus 
Explanation: Most common cause - Diabetes mellitus