As trees along a heavily shaded stream are cut down for farm land, the Environmental Protection Agency (EPA) must measure changes to the local stream habitat. Water samples from the stream are collected over time. The microorganisms are counted and classified in order to track changes.

EPA researchers MOST LIKELY used a __________ to view the microorganisms in the stream water samples.

A)
light microscope


B)
magnifying glass


C)
computer simulation


D)
scanning electron microscope