The human population grew more and more quickly over Time.
helped promote exploration, and economic interests
Answer:
In 1818, the United States and Britain agreed to occupy Oregon Country jointly. Spain and Russia had few settlers there, so they withdrew their claims to Oregon Country region's vast forests, trapping animals and living off the land. They were known as mountain men
Since the U.S. was fighting against communist nations in WW ll, I'd say answer A.
That was when the U.S. first realized how dangerous communism is, since the whole nation in a sense follows the wants of one man.
Fighting against Hitler, Mussolini, and the other guy (I can't remember who it was) really opened America's eyes to the horrors of communism, which is why they decided to strengthen the Democratic side of America.
I believe answer A. is correct.