What was the main reason that plantations were so profitable?

a. they planted cotton.
b. they used slaves to do all of the hard labor.
c. plantation owners were clever businessmen.
d. the land was so cheap.

what class is this for i can then

tenochtitlan (also spelled tenochtitlán), located on an island near the western shore of lake texcoco in central mexico, was the capital city and religious centre of the aztec civilization. the traditional founding date of the city was 1345 ce and it remained the most important aztec centre until its destruction at the hands of the conquering spanish led by hernán cortés in 1521 ce, which led to the final collapse of the aztec empire.