Answer:
(d) It uses a different definition for threatened than the IUCN.
Explanation:
The Endangered Species Act (ESA) was created with the purpose of preventing the extinction of plants and animals by protecting the ecosystems they depend on among other guidelines signed in the Act. It was signed in 1973. The International Union for Conservation of Nature (IUCN) is basically a thorough network of environmental organizations dedicated to the protection of Nature. It was founded in 1948. Both ESA and IUCN share a standardized terminology and same definitions for threatened species. On the other hand, there are some endangered species listed by IUCN that are not in the ESA list due to the fact that IUCN is an international organization.