Essayist: Earth is a living organism, composed of other organisms much as animals are composed of cells, not merely a thing upon which creatures live. This hypothesis is supported by the fact that, like all organisms, Earth can be said to have a metabolism and to regulate its temperature, humidity and other characteristics, divorced from the influences of its surroundings. Of course, Earth does not literally breathe, but neither do insects (they have no lungs), though they respire successfully.

The assertion that the insects do not literally breathe plays which one of the following roles in the essayist’s argument?
(A) A reason for not rejecting Earth’s status as an organism on the basis of its not breathing.
(B) A reason for rejecting as false the belief that Earth is a living organism.
(C) An illustration of the general claim that to be an organism, a creature must have a metabolism.
(D) An example of a type of organism whose status, like Earth’s is unclear.
(E) An illustration of a type of organism out of which Earth is composed.

Source: LSAT

Answer with Explanations
_________________