What are two ways carbon returns from animals into water

Two ways carbon return from animals into water is through cellular respiration and decomposition.

Cellular respiration is the chain of metabolic reactions and processes that happens inside the animals bodies which results to the release of waste products.

Decomposition happens when the animal dies and decomposes. The carbon in its body will then be absorbed by its surroundings; be it land, water, or air.

What are the choices