Answer:
its mostly all
Explanation:
but if I had to choose I would go with d,don't take my word for it tho sorry if this was not helpful
Tobacco, Rice, and Indigo were so work involved and Indentured Servants were expensive, so they decided to use African Slaves.
Take off D; the North had won some battles up to that point. Rip off A; the South would never let go of slavery. Take off B, since the Union had some wins already. You can now clearly see where the answer is.
They were hindered by economic development and lack of enforcement, so I'd say 1. Cost, because no one would pay for it.
