D, because skin tans to help us stand being in the sun without getting burned.
An example of physiological adaption is being able to digest milk. Before, humans were not able to digest milk before we developed enzymes that now make us have the ability to do so, thus allowing us another food source.
I think the answer is <span>sludge.
Hope this helped.</span>
-Both are organisms that must use energy to synthesize organic compounds
-Both require sunlight in order to survive
Freedom in American history and
