Answer:
C. They migrated over land from Africa over the last 80,000 years.
Explanation:
The most commonly accepted theory of how humans came to populate the world claims that humans originated in Africa from other, more primitive hominids. It was in Africa that modern humans began, and over thousands of years, they spread across the world. Different environments and needs led to the transformation of humans, which allowed them to develop different appearance and behaviour until there was an enormous variety among human populations of the Earth.