Luca Cavalli-Sforza Hypothesizes That Skin Color Change Came Late Because

Multiple Choice

Luca Cavalli-Sforza hypothesizes that skin color change came late because:

A) people used rudimentary umbrellas.
B) earlier populations had ready access to vitamin D from the foods they ate.
C) the Sun was not as powerful as it is today.
D) people were still migrating from a cold cloudy environment to a sunny environment.