in the first paragraph which sentence supports the idea that the economy of the south revolved around agriculture and slavery

A. People in the north worried that the south had intentions to expand slavery,which would make it hard for white laborers to find work

B. Many in the northern states felt that slavery was morally wrong but this was just one cause for concern

C. The south was completely committed to a single crop,cotton,which was picked entirely by slave labor.

D. The nation seemed to be splitting down social and political lines, becoming two different cultures that embraced very different ideas.