How does the renal countercurrent multiplier mechanism allow the creation of a concentrated urine?

A  It transports NaCl from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine.

B  By pumping NaCl and urea into the ascending limb of the loop of Henle, it raises the solute load, which turns into a concentrated urine once water is extracted from the collecting duct.

C  By concentrating NaCl in the renal medullary interstitial fluid, it allows water to be reabsorbed from the collecting ducts when vasopressin is present.

D  It transports urea from the medullary interstitial fluid into the collecting duct, which directly increases the osmolarity of the urine.

E  When anti-diuretic hormone is present, it stimulates the pumping of NaCl from the medullary interstitial fluid and water follows, concentrating the urine.