Answer:
C. loop of Henle
Step-by-step explanation:
The kidneys in the human body contains two types of nephrons , i.e , the juxtamedullary nephrons and the superficial cortical nephrons . .
Both of them having different functions and location .
The loop of henle is in the form of a hairpin like structure .
Now , the loop of henle in the cortical nephrons can penetrate only to the outer medulla of the kidney , but the loop of henle in the juxtamedullary nephrons can penetrate in the deep inner medulla .
both the nephrons are responsible for the regulation of the concentration of solutes and the water in blood .
And the counter current multiplication in the loop of henle is responsible for the developing osmotic gradients which is required to concentrate the urine .