Final answer:
Omnivores are organisms that act as both primary and secondary consumers because they eat both producers like plants and primary consumers like herbivores.
Step-by-step explanation:
The correct answer is C) Omnivores. Organisms that are both primary and secondary consumers are omnivores; they eat both plants and animals. Herbivores, like deer and rabbits, only eat plants, making them primary consumers. Carnivores, such as lions and hawks, feed on primary consumers making them secondary consumers. However, omnivores, which include humans, pigs, and bears, consume both producers (like plants) and primary consumers (like herbivores). Therefore, omnivores are the ones that fit the definition of being both primary and secondary consumers.
Decomposers, on the other hand, are organisms like fungi and bacteria that break down dead matter and recycle nutrients in the ecosystem; they are not consumers in the same sense as herbivores, carnivores, or omnivores.