A food chain always begins with a "producer" (as stated in).
Producers are organisms that make their own food using sunlight, water, and carbon dioxide through the process of photosynthesis. They are usually green plants or algae that use chlorophyll to capture sunlight and convert it into energy.
In a food chain, producers are eaten by primary consumers, which are then eaten by secondary consumers, and so on. Decomposers, which break down dead organisms and waste material, also play a crucial role in food chains, but they do not typically serve as the starting point of a food chain.
Therefore, a food chain always begins with a producer, as they are the first level of the chain, providing the basis of the energy and nutrients that support all other organisms in the ecosystem.