Context: Read the passage. Then answer the question below.

American bison roam in herds across the prairie grasslands in Montana. They are the only species of bison in North America. These large herbivores feed on the dozens of species of grasses that grow on the prairie, such as Idaho fescue and rough fescue.
American bison are large enough that they are difficult for predators to capture. Instead of running away when attacked, they fight back as a group. Still, they are sometimes hunted by wolves, mountain lions, and grizzly bears.
Figure: a herd of American bison on a prairie.
Which of the following best describes a population on the prairie grasslands of Montana?
A. a herd of American bison
B. the Idaho fescue and the rough fescue
C. the wolves, the mountain lions, and the grizzly bears
Select the correct answer from the given choices and respond with the letter of the chosen option.

A