During most of our species' 160,000-year existence, and until about 10,000 years ago, we depended on
a. crops
b. hunting and gathering
c. hunting
d. crops and cattle
e. cattle

The second one is the answer edg.

It is the doctrine that the us had the right and duty to expand throughout north america. it just means they believed they had the right to expand westward and they did! they stated with the 13 colonies and then they kept moving gaining different territories throughout the years