Which of the following statements is correct regarding the reabsorption of $K^+$ (Potassium) in the nephron?

In the distal convoluted tubule $(DCT)$ of the nephrons:

Which process is responsible for the excretion of drugs and toxins from the blood into the filtrate?

Match the following columns:

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

The brush border is a characteristic of which of the following?

$I.$ Reabsorption of water occurs passively in the initial segment of nephron.
$II.$ Nitrogenous wastes are absorbed by active transport.
$III.$ Conditional reabsorption of $Na^{+}$ and water takes place in $DCT$.
$IV.$ $DCT$ reabsorbs glucose.
$V.$ $DCT$ is capable of selective secretion of $H^{+}$,$K^{+}$ and $NH_{3}$ to maintain $pH$ and $Na^{+}-K^{+}$ balance in blood.
$VI.$ Substances like glucose,amino acids,$Na^{+}$,etc.,in the filtrate are reabsorbed actively.
Choose the option with incorrect statements.