Which of the following statements is/are incorrect regarding the collecting duct?
(i). It extends from the cortex to medulla.
(ii). Large amount of water could be reabsorbed by it to produce concentrated urine.
(iii). Small amount of urea diffuses into it from the medulla to keep up the osmolarity.
(iv). it plays a role in maintaining pH and ionic balance of blood by the selective secretion of `H^(+)` and `K^(+)` ions.

Options

A. Only (i)
B. Only (iii)
C. (ii) and (iii)
D. (i) and (iv)

Answer

B

Explanation

Collecting duct also allows passage of small amounts of urea into the medulla to keep up the osmolarity