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
___________  percentage of Na+ is reabsorbed from ascending loop of henle via ___________ transporter. 
Select and explain. 
A. 20, Na+ – H+ exchange, B. 40, Na+ - K+ - 2Cl– symporter, C. 30, Na+ – Cl– symporter, D. 20, Na – K- 2Cl–  symporter
D: 20, Na – K- 2Cl–  symporter
Answer: D: 20, Na – K- 2Cl–  symporter 
Explanation: % Na reabsorption
Site
Main mechanism


60 – 70%
PCT
Na+ – H+ exchanger


20 – 25%
Ascending loop of henle 
Na+ – K+ – 2Cl– symporter


10 – 12%
DCT
Na+ – Cl+ symporter


3 – 4%
Collecting duct
ENAC channel