Natural selection that favors the one extreme in the range of variation for a phenotype is called:
disruptive selection
directional selection
stabilizing selction
none of these

This type of natural selection is referred to as directional selection. In this type of natural selection, either one phenotype is preferred or the other; therefore, there is no equilibrium between the populations of the phenotypes that are present.
Examples of organisms that have undergone directional selection are black bears during the ice ages, African chichlid and sockey salmon.