On Which Continent Would You Expect to Find the Most

On which continent would you expect to find the most human genetic diversity and why?

A) Africa, because it has the oldest human populations, containing alleles that originated long ago and have evolved since.
B) Australia, because it has the oldest human populations.
C) Australia, because it has had a relatively small population size for a relatively short amount of time.
D) Europe, because it had waves of human migration from other parts of the world over the course of many thousands of years.
E) South America because it was one of the last continents to be inhabited by humans.