It should be A, since before the Spanish came, there were no horses in the America's. With horses, the Indians were able to hunt more efficiently and had a better way of transportation.
By the way, can you answer one of my questions? Thanks!
Coastline,rivers,and low elevation
What caused the French Revolution? Simple answer: They really didn't want to pay taxes and the cost of the food was high for them. So they went to war...