This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Kidneys and Body Fluids, Subject name: Physiology
Thick Ascending Limb of loop of Henele has which channels- 
Select and explain. 
A. Na+ C1- cotransporter, B. Na+ - 2C1- - K+ cotransporter, C. ENaC channel, D. Na+ - aminoacid cotransporter
B: Na+ - 2C1- - K+ cotransporter
Answer: B: Na+ - 2C1- - K+ cotransporter 
Explanation: Ans. is 'b' i.e., Na+ - 20- - K+ cotransporter * In the thick ascending limb, a carrier (Na+ K+ 20" transporter) transports one Na+, one K+, and two Cl- from the tubular lumen into the tubular cells. This is another example of secondary active transport. From the cells Na+ is actively transported to the peritubular interstitium, across the basolateral membrane, by Na+ K+ ATPase. The K+ diffuses back into the tubular lumen and into the interstitium via ROMK and other K+ channels.