Assertion A: The renal fluid becomes increasingly concentrated when it flows down in the descending limb of loop of Henle towards the inner medulla but its concentration decreases in the ascending limb when it flows towards the cortex
Reason R: The descending limb of the loop of Henle reabsorbs water, the ascending limb is impermeable to water but salts are reabsorbed
A. Both A and R are true, R is correct explanation of A
B. Both A and R is true, R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true
