Following the Civil War, Texans and settlers from the Southern states began moving westward to open lands in the High Plains and West Texas. Not all Native Americans living there were willing to move to reservations. In addition to battles with the U.S. Army, which of the following events finally defeated the Native Americans and pushed them onto reservations?
A) diseases that spread through the tribes
B) fighting among the different tribes
C) pressure from settlers from New Mexico
D) the slaughter of the buffalo herds