Answer: Region C
=============================================================
Step-by-step explanation:
Check out the screenshot below.
I formed a fourth column where we divide each population over its corresponding area. For example, region A will have a population density of roughly 1312/212 = 6.19 which means there are 6.19 zebras per square km.
The higher the population density, the more competition for resources. We see that region C has the highest density at about 26.24 zebras per square km. There are more zebras competing for food/water/shelter/etc in the same relative area compared to the other regions.