How is an organism's
metabolism related to the Earth's
carbon cycle?

Metabolism involves either using energy to build organic molecules or breaking down organic molecules in which energy is stored. Organic molecules contain carbon. Therefore, an organisms metabolism is part of Earth's carbon cycle.

Explanation:

in other words:

An organisms metabolism is related to the earth's carbon cycle because metabolism involves either using energy to build up or breaking down organic molecules in which energy is stored. Organic molecules contain carbon.

Hope this helps :)

b is the correct answer