Ans) 1.3 bison/mile
Soln:} See according to the question, Yellowstone National Park has an average of about 4500 bison living in it.
Area covered by Yellowstone park is 3472 miles.
So, to find the density of bisons living in Yellowstone Park we have to divide the no. of bisons by given area.
= 4500/3472
which is approximately 1.3 bisons per mile.
Therefore option a) is correct
Hope it helps!!!