Why Was Cotton Production an Important Development in the South

Why was cotton production an important development in the South in the late-eighteenth and early-nineteenth century?

A) Demand for cotton was skyrocketed, and slaves were needed to pick it.
B) The South became more industrialized and needed more slaves.
C) Cotton production generated income for the South at the expense of the North.
D) Cotton production helped attract European immigrants to the U.S.to process the crop.