Final answer:
Organisms fall into the categories of producers or consumers. Producers (autotrophs) create their own food, while consumers (heterotrophs) obtain energy by eating other organisms. Decomposers, not given as an option, also play a vital role in ecosystems.
Step-by-step explanation:
All organisms fit into one of the following categories: producers and consumers. Producers, or autotrophs, include photosynthetic organisms like plants and phytoplankton, which are able to make their own food through photosynthesis or chemosynthesis and serve as the foundation of food chains in ecosystems. Consumers, or heterotrophs, are organisms that cannot produce their own food and must eat other organisms to obtain their energy. They include herbivores that eat producers, carnivores that eat other animals, omnivores that eat both plants and animals, and fungi and certain protists and bacteria that absorb nutrients from their environment. There is also a third category not listed in the choices: decomposers. Decomposers break down dead organisms and organic waste, releasing simple inorganic molecules back into the environment, which in turn can be utilized by the producers. Therefore, the correct category that encompasses all organisms would be 'producers and consumers'.