Which species in the United States are protected under the Endangered Species Act?

all species of birds and mammals

all species in wilderness areas

all species affected by habitat loss

all species at risk of dying out

The answer is "all species at risk of dying out".

The Endangered Species Act was created in 1973 to protect all endangered species in the United States, meaning species whose situation, including rapid habitat loss and low population, puts them in danger of going extinct.