What is a geographic reason for the differences in the way native american groups lived?

a. as they came in contact with people in different parts of the continent, native americans copied what they saw.

b. as people spread across north america, they adapted to the different kinds of terrain and climate they found.

c. native american groups chose where to live based on the climate and terrain they preferred.

d. tall mountains and wide rivers prevented any contact or trade between native american groups.