The answer is A. populations of the same species may be separated and would no longer be able to mate.
Mountain lions in Los Angeles are a victim of habitat fragmentation. We have built houses and roads throughout Southern California. This has cut through a lot of mountain ranges mountain lions live in. Mountian lions do not live in packs and tend to stay distant from each other. They still need each other to reproduce. We as humans have isolated them even more by fragmenting their habitats. Freeways and humans have killed mountain lions as well.
The lack of mountain lions will cause them and have caused them to mate with closer relatives. This is like when a person sleeps with their cousin or their father. It is not healthy because children may come out with defects. Then eventually the population of mountain lions will dwindle because they cannot survive