What groups of animals do geologists classify

the correct answer is:

a population changes in response to a change in the environment.

kelp are large brown algae that live in cool, relatively shallow waters close to the shore. they grow in dense groupings much like a forest on land. these underwater towers of kelp provide food and shelter for thousands of fish, invertebrates, and marine mammal species.

e) all of the above

i think the answer is a.keratin is the pigment responsible for skin color.