Answer:
The answer is: D: Humans domesticating corn.
Explanation:
There have been many theories on how large mammals and other animals became extinct in North America, when they were present in great numbers around 11.000 years ago. One of the main events explained by paleontologists, is the coming of human migrants for the first time from Asia into the Americas, because their hunting activities led to this mass extinction. They domesticated a lot of animals which caused the loss of the wilder versions of them, like dogs. They also learned how to use fire, which increased human capacity to hunt and kill these large animals, both as food and also as defense mechanisms. Finally, another theory comes from the environment. Several scientists believe that one of the reasons had to do with the weather, especially ice ages and global warming, but there is no certain answer yet. The only reason not provided, however as a possible cause for extinction of large mammals in North America is the domestication of corn by humans.
