C. Were not protected as promised by the United States. (apex)
Explanation:
There were of course other factors. While early humans did hunt them a lot due to the profits which they received from it (A lot of food, bones they could use for homes, fur they could use for clothing, etc.), there were also other factors such as less food for them which made them less mobile through different geographical regions, etc. (and therefore more susceptible to being hunted) that had played a part in their extinction.
Simple. The Columbian Exchange exchanged diseased, people, plants, food, and animals. The Americas adapted with new plants and animals like cattle, chicken, etc., and more slaves. Europe gained potatoes, tomatoes, corn, squash, punpkin, etc.
New societies could depend on new sources of food, new animals. That also improved their local economy, and knowledge (learning)
