Which factor made some colonies more likely to exploit large numbers of enslaved africans

I think you are supposed to have answer choices posted.
Anyways, here are some factors that made some colonies exploit large numbers of enslaved Africans: 

1) The increase of money which lead to more work needed to be done so people needed more slaves.

2) Competition, as people compete to have money, which in that time needed more slaves so they can have more work done and more money.

The common sense pamphlet i think