Under the ESA, species may be designated as which of the following?

The Endangered Species Act (ESA) specifically establishes criteria for the classification of species into categories that denote their conservation status. Under the ESA, the classifications primarily used are "endangered" and "threatened."

An "endangered" species is one that is at risk of extinction throughout all or a significant portion of its range, indicating a critical need for protection. In contrast, a "threatened" species is one that is likely to become endangered in the foreseeable future. These classifications guide the protective measures and conservation efforts required to help stabilize and recover populations of these species, ensuring their survival.

The other classifications presented in the options either do not align with the terminology used in the ESA or do not accurately reflect the distinctions made within the act. For example, while the concept of "protected" might imply a level of conservation, the specific terms recognized by the ESA are "endangered" and "threatened."