Question

which organisms release carbon dioxide as waste?
consumers only
consumers and decomposers
producers and decomposers
producers only

Explanation:

Consumers (heterotrophs) perform cellular respiration, which breaks down organic molecules (like glucose) to release energy, and carbon dioxide is a by - product. Decomposers (such as bacteria and fungi) also carry out cellular respiration as they break down dead organic matter. Producers (autotrophs like plants) mainly take in carbon dioxide for photosynthesis (although they do respire and release some carbon dioxide, but the question is about which group "release carbon dioxide as waste" in a more prominent sense in the context of the options). Consumers and decomposers are the main groups that release carbon dioxide as a significant waste product from their metabolic (respiration) processes.

Answer:

consumers and decomposers