Final answer:
Both consumers and decomposers release carbon dioxide as waste through the process of cellular respiration and decomposition of organic matter, respectively.
Step-by-step explanation:
The organisms that release carbon dioxide as waste include both consumers and decomposers. Consumers, such as animals and other heterotrophs, take in organic compounds produced by producers and release carbon dioxide (CO2) into the atmosphere through cellular respiration. On the other hand, decomposers, which include bacteria and fungi, break down dead organic matter and release CO2 in the process. Therefore, the correct answer to which organisms release carbon dioxide as waste is b. Consumers and decomposers.