Answer: B. Producers
Step-by-step explanation:
A food chain is basically a sequence of transfer of food and energy when one organism is consumed by other organism in an ecosystem. In an energy pyramid linked with food chain the producers are present in the lowermost base level trophic level. These organisms exhibit the highest amount of energy as compared to other trophic levels. As these organisms are capable of producing their own food by process of photosynthesis by obtaining the energy from sunlight or by chemosynthesis. This energy decreases in subsequent trophic levels when producers are consumed by consumers.