Answer:
Disruptive selection
Step-by-step explanation:
Disruptive selection is a type of natural selection that occurs when the extreme phenotypes have increased survival fitness that the phenotypes with the intermediate trait. The disruptive selection favors the extreme phenotypes at the expanse of the intermediate phenotype.
In the given example, the intermediate phenotype (the gray mice) have lesser survival fitness as they are visible to predators. The disruptive selection does not favor gray mice and leads to the evolution of populations of black and white mice.