Answer:
D) the hunting of buffalo by U.S citizens
Explanation:
The hunting of buffalo by U.S. citizens had an immediate and direct impact on the Native Americans of the Great Plains. They used the buffalo for meat, tools, and housing. Hunters, however, usually just killed the buffalo for their skins, leaving the rest to rot on the prairie. The hunts occurred too often and too fast, wiping out the previously plentiful herds.
