Final answer:
Decomposers play a crucial role in ecosystems by breaking down dead organic matter and recycling nutrients and materials, making them available for use by producers. The accurate claim about decomposers' role is that they recycle energy and materials from dead organisms, with the correct answer being Option D.
Step-by-step explanation:
The primary role of decomposers in an ecosystem is to break down dead organisms and other organic wastes, thereby recycling energy and materials back into the ecosystem.
Decomposers, such as bacteria and fungi, are vital for ecosystem health because they carry out the process of decomposition, which involves the breakdown of complex organic materials into simpler inorganic substances. These substances are then available for uptake by producers, such as plants, which can utilize them to create new organic compounds through photosynthesis. This process is critical for the cycling of nutrients in the ecosystem and ensures that essential elements like carbon and nitrogen are available to support various life forms.
When considering the options provided, the claim that accurately identifies the primary role of decomposers is that they recycle energy and materials from dead producers and consumers (Option D). Decomposers do not control populations or directly provide energy to producers; instead, they play a foundational role by decomposing organic matter, thus facilitating nutrient recycling and maintaining the flow of energy in the ecosystem. Therefore, the correct option is D.