A group of white, grey, and black rabbits lives in Alaska, where there is usually snow on the ground. Wolves that hunt the rabbits end up mostly catching ones with grey and black fur. As a result, white rabbits become more prevalent in the population. This is an example of:

Directional selection

Explanation:

Natural selection is the process by which environment selects from a population of organisms which individuals are better suited and adapted to that environment. There are three types of natural selection namely: directional selection, disruptive selection and stabilizing selection.

Directional selection is the type of natural selection in which only one extreme (phenotype) of a population is favored over the other extreme and intermediate individuals. This is the case in the example given in the question where among a group of white, grey, and black rabbits that lives in Alaska, environment selects the white rabbits (one extreme) from wolf predation, hence, causing the white rabbit population to increase and be favored.