In a species of ground finch that inhabits the galápagos islands, the average beak size increased over several generations from 9 mm to 10 mm after a drought that left only large hard seeds for the finches' food source. this is an example . stabilizing selectionb. genetic driftc. disruptive selectiond. directional selection

d. directional selection

Explanation:

Directional selection is a form of natural selection that occurs when a particular extreme phenotype of a species is highly favored and thrives more than the other extreme phenotype. This is particularly influenced by environmental changes resulting in differences in the survival between both extreme phenotypes.

In the Galapagos Islands during drought, the seeds to be fed on by finches are mostly large in size, giving rise to the survival of only finches with large beak size of 9 mm to 10 mm as against finches with small beak size. Finches with large beak sizes are favored over  finches with phenotypic traits of small beak sizes.