How was American Democracy changed over time?

i believe your answer is d)

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

answer is b.

  it is always the best policy to have good communication and good relations between individuals and, specially, between leaders of the countries. for this purpose, among others, there is a common place, the united nations, where the representants can present his and learn about the other country's policies.

the red river i think.