Which one of the following is mismatched?

Reabsorption of useful substances from the glomerular filtrate occurs in the:

Glucose is reabsorbed from the glomerular filtrate by ......... .

$I.$ 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.

Part of the nephron where conditional reabsorption of $H_2O$ and $Na^+$ occurs is:

Which of the following pairs is incorrect?