What event had the most immediate impact of native americans who lived on the great plains?

ok so u have2 basically

c

explanation:

food chain i would say only because there is competition on getting food and survival

answer: ensure protection from communism

explanation:

the north atlantic treaty was largely dormant until the korean war initiated the establishment of nato to implement it, by means of an integrated military structure: this included the formation of supreme headquarters allied powers europe in 1951, which adopted the western union's military structures and plans.