Reabsorption of useful substances back into the blood from the filtrate in a nephron occurs in

$A :$ Tubular secretion is of considerable importance in marine teleost fishes.
$R :$ These have aglomerular kidney,$i.e.$,no filtration occurs and tubular secretion is the only way of excretion.

Provide the full names for the following abbreviations:
$(1)$ $PCT$
$(2)$ $DCT$

Hormone responsible for the absorption of water in $DCT$ is

Given below are two statements:
Statement $I$: In the nephron,the descending limb of the loop of Henle is impermeable to water and permeable to electrolytes.
Statement $II$: The proximal convoluted tubule is lined by simple columnar brush border epithelium and increases the surface area for reabsorption.
In the light of the above statements,choose the correct answer from the options given below:

Which one of the following is not a part of a renal pyramid?