This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Kidney Disease & Diabetic Nephropathy, Subject name: Medicine
Which of the following is used for staging of CKD? 
Select and explain. 
A. e-GFR and serum creatinine, B. e-GFR and serum albumin, C. e-GFR and urine output/d, D. e-GFR and albuminuria
D: e-GFR and albuminuria
Answer: D: e-GFR and albuminuria 
Explanation: e-GFR and albuminuria- used for staging of CKD