The correct answer is B. The americas
The Americas provided raw materials that were taken to Europe. Europeans manufactured goods from these materials and traded them to Africans in exchange for slaves. Slaves were then taken to the Americas to get new raw materials. That's how the triangle worked.
European Imperialism was a period of colonial expansion. It is the most important cause of WW1 because it built tension between the countries. It caused Tension between Nations and Countries. Was a cause of WW1 by separating from where they stand to form another empire away from their old empire, to avoid dictatorship.
That black people (not just slaves) had no rights in america and their fore couldn't even bring a law suit.