Which answer is the right one???

it is c that's right I pretty sure

answer:

it caused mass african migration, african populations to grow, african empires to topple, and racism against slaves to emerge.

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.