Ascientist who is researching marshes observes that marsh grass, spartina bakeri, grows to different heights at different locations in the marsh.
if the scientist wants to find the reason for this difference, what is the correct first step?

a) conduct an experiment and change only one variable at a time.

b) determine which technology would assist most in answering the question.

c) make an inference based on knowledge of the marsh.

d) establish a control group for comparison.