Answer: The correct answer for the blank is Environmental Protection Agency (EPA).
EPA stands for Environmental Policy Act/ Agency. It was one of the first laws that was established by U.S congress in 1969, with the framework of protection of our environment. This agency conducts assessment of environment, education, research on regular basis to help with the problems of pollution in the environment.
It has taken the responsibility of maintaining and enforcing national standards, which lie under environmental laws.