The correct response is:
The wolves increased the population by eating beavers’ predators.
The reintroduction of wolves to Yellowstone National Park helped balance the ecosystem. By preying on elk, which were overpopulated and consuming a significant amount of vegetation, the wolves allowed for the regrowth of riparian areas. This, in turn, created better habitat conditions for beavers, leading to an increase in their population as they benefited from the healthier ecosystem.