he efficiency and productiveness of many large cotton plantations found in the south during the first half of the 19th century made most plantation owners economically dependent on A) slave labor. B) hired field hands. C) captured Native Americans D) wage earning white workers.

The Southern Plantation owners could not conceive a world without slaves. They were the ones who did all the hard work, and lived in very poor health conditions and so were cheap workers. They tried to enforce the idea that the black Africans should be enslaved and they (as white) had the right to own people. The laws favoring free states and the decision of some northern states of not following the Fugitive Slave Act were some of the reasons the the Southern states united in as Confederate States of America.

After the war and enslavement abolition, the black people continued working on plantations, under very bad conditions.

So, the right answer would be A - Slave Labor.

A) Slave labor