What is the primary role of cortical nephrons?

Match the following columns:

Column-$I$	Column-$II$
$a. PCT$	$i. \text{Selective secretion of } H^+ \text{ and } K^+ \text{ ions}$
$b. DCT$	$ii. 70-80\% \text{ of electrolytes and water reabsorption}$
$c. \text{Descending limb}$	$iii. \text{Allows passage of small amounts of urea}$
$d. \text{Ascending limb}$	$iv. \text{Permeable to water}$
$e. \text{Collecting duct}$	$v. \text{Permeable to salts}$

Distinct microvilli are present on all of the following except:

Statement $I$: Collecting duct of kidney extends from the cortex to the inner parts of medulla.
Statement $II$: Large amount of water could be reabsorbed from collecting duct to form a concentrated urine.

Passive transport occurs in the case of

In which part of the nephron does the maximum reabsorption occur?