Which process results in the release of carbon? select three options

Carbon is one of the essential gases in nature,couple of natural processes causes the release of carbon. Some of the processes include;

- When the remains of producers are broken down by decomposers in the ecosystem.

- When animals break down food molecules to obtain energy, carbon is released.

- When the remains of consumers in the ecosystem are broken down by soil decomposers, carbon is released.

the correct answer is d