Typically, the main reason why the Europeans decided to rely on the
Africans for labor on American plantations rather than on American
indigenous people because Africans are longed been exposed to small pox
and they have already developed immunity in most of the common European
diseases.
You have not included "the following," but it is possible to answer this question by saying that Europeans relied primarily on Africans rather than on American indigenous peoples for labor because the former were significantly more resilient and immune to the microbes conveyed by the Europeans than the latter. It must be added, nevertheless, that the American Indians were also slaved in large numbers and sent to work in areas like the West Indies or Mexico.
The correct answers is C. Socialism (as a political ideology)arose as a response to the the way in which the industrialization of Europe dramatically affected the everyday lives of individuals (the working class in particular). This political ideology was, therefore, an economic and social consequence of the Industrial Revolution.