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: Pharmacology
Indication of ACE inhibitor in diabetes mellitus is: 
Select and explain. 
A. Diabetic nephropathy, B. Nephropathy unrelated to diabetes, C. Both, D. None
C: Both
Answer: C: Both 
Explanation: None