Which statement best describes why modern horses look the way they do?

Question

a. Aspects of horse anatomy evolved over millions of years to suit their environment.
b. Aspects of horse anatomy evolved over hundreds of years to suit their environment.
c. Aspects of horse anatomy evolved within a generation to suit their environment.
d. Aspects of horse anatomy evolved within a few generations to suit their environment.

Answer 1

a. Aspects of horse anatomy evolved over millions of years to suit their environment.