Question

a warming climate 12,000 to 10000 years ago impact the Paleo-Indians living in the Americas at that time

Answer 1

A warming climate meant that more edible plants were available: it means that people could rely better on gathering food. 
It also meant that fishing was easier for many reasons. - the correct answer  is c
It made the food generally more abundant, so it did not lead to extended wars. Also there was still plenty of land left, so the Indians didn't loose a significant amount of land.