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
Clinical feature of CRF appear when renal function is reduce to - 
Select and explain. 
A. 70%, B. 50%, C. 30%, D. 20% of normal
D: 20% of normal
Answer: D: 20% of normal 
Explanation: None