What was a commonality shared between the Asians who crossed the Bering Strait and the Europeans who crossed the Atlantic Ocean thousands of years later?

a$)$ Both groups were driven by the desire to hunt large mammals.

b$)$ Both groups were searching for resources.

c$)$ Both groups trekked during bitter ice ages.

d$)$ Both groups were sent there by powerful monarchs.

e$)$ Both groups started as slaves and then gained their freedom during the journey.