Greyhounds, a dog breed, were produced by humans breeding the fastest males and fastest females from each generation. what is this called?

Artificial selection

This is called artificial selection .

Artificial selection is a process by which humans choose and use animals and plants with desirable characteristics (phenotypic traits) to reproduce and have offspring together. Farmers usually select cattles with beneficial characteristics such as high milk production, and made them breed. The more these characteristics are demonstrated in the offspring, the more they are said to be transmissible.

the answer for this question would be d. glaciers