Answer:
Answer: Plains occur as lowlands along the bottoms of valleys or on the doorsteps of mountains, as coastal plains, and as plateaus or uplands. ... Plains may have been formed from flowing lava, deposited by water, ice, wind, or formed by erosion by these agents from hills and mountains.
Well I think it's gonna be C - 90° N and 90<span>° S - because those latitudes are located exactly on both north and south poles and there's nothing more likely to see glaciers than the poles themselves.</span>
The first natives came from Asia the part that is now known as Siberia Russia
So your answer is (A) Asia