Which of the following best exemplifies primary producers in an ecosystem?

Primary producers are organisms that can produce their own food through the process of photosynthesis or chemosynthesis, forming the base of the food chain in an ecosystem. In terrestrial ecosystems, plants are the most common primary producers. They capture sunlight and convert it into chemical energy in the form of glucose, which can then be used by themselves and other organisms within the ecosystem.

Herbivores, decomposers, and predators all rely on the energy produced by primary producers. Herbivores consume plants, decomposers break down dead organic matter including dead plants and animals, and predators typically rely on herbivores or other consumers for energy. Therefore, while they play essential roles in the ecosystem, they do not produce energy in the same way that plants and other primary producers do. Plants, as primary producers, are crucial for the energy flow within an ecosystem, making them the best exemplification of this group.