How Is the Loop of Henle Important in Concentrating Urine

How is the loop of Henle important in concentrating urine if the fluid leaving the ascending loop of Henle is very diluted?

A) The proximal convoluted tubule concentrates the urine after it exits the loop of Henle.
B) The loop of Henle concentrates the urea that is excreted in the collecting duct.
C) The loop of Henle is responsible for creating the concentration gradient used by the collecting duct to concentrate the urine.
D) The loop of Henle is responsible for storing the NaCl used to concentrate the urine in the colleting duct.