What are the main organs of the skeletal system?

bones, ligaments, tendons and joints hope this helps! :)

The correct answer is D. stay the same

Explanation:

In a communalistic relationship between two individual one individual get benefits from its partner and the second individual is not harmed or benefitted with the presence of first partner.

So in case of symbiotic relationship between barnacles and whales, barnacles get benefited by attaching to the whale body which helps it collect food from passing waster and it does not affect whale in a positive or negative way.

So as the whale is not affected by the presence or absence of barnacles, therefore, there will be no change in the population of whale when the barnacle population will decrease. So the correct answer is D.