Question

which species were reintroduced to yellowstone national park that had overall positive impact there? wolves beavers elk

Explanation:

The reintroduction of wolves to Yellowstone National Park had a significant positive impact on the ecosystem (e.g., regulating elk populations, improving vegetation, and enhancing biodiversity). Beavers and elk were not reintroduced for this positive impact in the same context.

Answer:

A. Wolves