I think its a because risk actually means exposure to danger our sacrifice your self plz mark as brainly
It is difficult to control all variables except the one being tested. Hope this helps.
Answer:
c
Explanation:
An experiment in which an observer tests a hypothesis by looking for changes brought on by alterations to a variable. In a controlled experiment, an independent variable is the only factor that is allowed to be adjusted, with the dependent variable as the factor that the independent variable will affect.
in Basic terms The control group provides a baseline that lets us see if the treatment has an effect.
"Their habitats may range from the surface water to the ocean trenches. Marine organisms are classified<span> by how they move and where they live."
Hope This somehow helps~
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