What makes a baseball bounce would be the correct answer. All the other options would be opinions, therefore they are not true testable experiments. Hope this helps!
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.
Something scarce is something that is not found easily. It is sometimes limited therefore it is RARE.
Your answer would be rare. :) Hope I helped. :D