Final answer:
The Endangered Species Act is responsible for monitoring threatened and endangered species and their habitats, focusing on individual species rather than ecosystems. The correct answer is option: a) Threatened and endangered.
Step-by-step explanation:
The Endangered Species Act assigned governmental agencies the responsibility to monitor threatened and endangered species and their habitats. This law, enacted in the United States in 1973, gives the U.S. Fish & Wildlife Service the duty to develop management plans that aim to protect these species and increase their numbers to sustainable levels.
Despite its intentions, the Act faces challenges such as the difficulty in getting species listed and in implementing effective management plans. Additionally, it has been criticized for its focus on individual species rather than broader ecosystem protection.