Answer: Photosynthesis
Explanation:
The process which provides the initial energy for all the levels is known as photosynthesis. This is because the energy from the sun can only be trapped in plants and then transferred to other levels for providing energy.
The primary consumer feeds on the producers for energy, the secondary consumers feeds on the primary consumers for food and so on.
This shows that if there are no plants then there will be no energy available to the other levels.
