Answer:
D. the Sun
Step-by-step explanation:
Pyramid of energy is a model used to depict the flow of energy from one trophic level or feeding level to the next in an ecosystem. It's a diagram that compares the energy used by organisms at each trophic level of the food chain. The pyramid of energy must never be inverted or turned upside down.
The units used in the construction of pyramids of energy is kilocalories (kcal) or energy per area per time (Jm-²year-¹).
In Biology, producers are the living organisms that are capable of manufacturing their own food and as such can provide energy or food for the other living organisms in a food chain. Thus, producers are mainly known as the foundation of a food chain and are at the top.
A producer gets energy from the sun and converts it into food. The cells found in producers are capable of converting the energy received directly from the sun into food through a process generally referred to as photosynthesis, converting carbon dioxide from the air, water from the soil, minerals and energy from the sun into organic nutrients.