I guess it is one of b and c
but my 98% consent is with B option: technology is increasingly <span> replacing </span>physical<span> human labor.</span>
The correct answer is d. combustibility
slavery was an important factor in the south because in the south it mainly crops and not Industrialized , so all the harvesting and planting was labor Intensive with slaves the southerns wouldnt have to do it plus there were not that many willing to tend the crops which make the slaves the mostly the way of making money on plantions.
