Primary contributions to United States economy:

your answer would be (b)

disease was the number one killer of native peoples. they had had little exposure to the diseases of europe. this led to some villages being almost completely wiped out and some tribes destroyed.

explanation:

i think it is in quadrant 4.

the five year plans were part of a command economy. there was little choice in what would be emphasized for the current 5 year period.

the answer to democracy or totalitarianism is a bit harder. in stalin's time, russia was totalitarian. now that's not entirely true. putin has moved towards at least the boundary.

d. william mckinley's southern upbringing him win.