D. Owners of sugar plantations needed slave labor.
The Atlantic slave trade involved the transportation of millions of enslaved Africans from Africa to the Americas to work on plantations, particularly in the production of sugar, tobacco, cotton, and other cash crops. The demand for enslaved labor was particularly high in the Caribbean and Brazil, where sugar plantations dominated the economy. European colonizers and traders established the slave trade to meet the labor demands of these plantations and to maximize their profits. Native Americans were also enslaved and forced to work in various capacities in the Americas, but the scale of the Native American slave trade was much smaller than that of the African slave trade, and it was largely supplanted by the African slave trade in the 17th century.