D: studying how the mayfly population affects the number of trout in a stream
What is Ecology?
Ecology is the study of organisms and how they interact with the environment around them.
How mayfly is related to Ecology?
Mayflies provide direct and indirect services to humans and other parts of both freshwater and terrestrial ecosystems.
About 20% of mayfly species worldwide might have a threatened conservation status due to influences from pollution, invasive alien species, habitat loss and degradation, and climate change.
Thus, option D. is correct.
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