Final answer:
Based on the provided descriptions, the type of selection that selects for extreme phenotypes and against the average phenotype is known as disruptive or diversifying selection. Option c is the correct answer.
Step-by-step explanation:
Selection, which is the process by which certain phenotypes are favored to survive and reproduce, can lead to a shift in the phenotype frequency of the next generation. The type of selection represented by the described graph can be identified by knowing the patterns of phenotypical changes in a population.
When the average phenotype is favored and extreme variations are selected against, this is known as stabilizing selection. If the environment changes and causes the distribution of phenotypes to shift toward one extreme, it is called directional selection. When two or more extreme phenotypes are favored over the average, it is known as diversifying selection.
Based on the provided information, which mentions selection against the middle range phenotypes and selecting for the extremes, the correct answer would be disruptive selection, also sometimes referred to as diversifying selection.