A Scientist Monitors Both the Pollution Entering a City's Water

Multiple Choice

A scientist monitors both the pollution entering a city's water supply and the changing populations of fish and other organisms thought to be affected by this pollution. He also speaks regularly at city council meetings, giving the results of his studies, and suggests changes in local laws that could help control the pollution. Based on his activities, this person could best be described as

A) an ecologist.
B) an environmental scientist.
C) a politician.
D) an activist.