This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
What is the GFR (mL/min per 1.73m2) of a patient who is in stage IV of chronic kidney disease? 
Select and explain. 
A. 60 - 89, B. 30 - 59, C. 15 - 29, D. < 15
C: 15 - 29
Answer: C: 15 - 29 
Explanation: .