Answer: The correct answer is-
Flow of energy in an ecosystem ( a large community of life forms that interact with each other as well as their physical environment in a particular area) takes place through food chain.
A food chain is a linear network of different organisms ( occupying different trophic levels) where organisms at one trophic level consumes organisms at previous trophic level and energy flow takes place in the form of organic matter.
Producers ( such plants) prepare their own food through photosynthesis and occupy the first trophic level.
Producers are eaten by primary consumers ( which are generally herbivores such as rabbits).
Primary consumers are eaten by secondary consumers, which are then eaten by tertiary consumers that are eaten by final consumers and then decomposers ( such as Fungi).
Example- Grass → Grasshopper → Frog→ Snake → Hawk → Fungi