1^st part ? please explain by giving a reason ??????????

The normal bell curve in graph a is changed greatly in disruptive selection i.e. graph b.
Disruptive selectionis a type ofnatural selectionthat selects against the average individual in a population. The make up of this type of population would showphenotypesof both extremes but have very few individuals in the middle. Disruptive selection is the rarest of the threetypes of natural selection.