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: Physiology
Juxtamedullary nephrons in kidney are what percentage of total nephrons 
Select and explain. 
A. 15, B. 50, C. 70, D. 90
A: 15
Answer: A: 15 
Explanation: A i.e. 15%