Which of the following is incorrect for `p`-block elements?

Options

A. Some of the elements exhibit variable valencies.
B. Some of the elements exhibit variable oxidation numbers.
C. Lighter elements exhibit inert pair effect.
D. The highest oxidation number shown by a `p`-block element is equal to the sum of `ns`- and `np`-electrons in the valence shell.

Answer

C

Explanation

Inert pair effect is the characteristic of the heaviest elements of `p`-block.