Although We Must Be Cautious About Oversimplifying, When Visible Traits

Although we must be cautious about oversimplifying, when visible traits are markedly different among human races, a likely explanation is that the differences have been favored by:

A) natural selection and/or sexual selection.
B) diversifying selection and/or stabilizing selection.
C) allopatric speciation and/or sexual selection.
D) disruptive selection and/or natural selection.
E) sympatric selection and/or sexual selection.