Answer:
Trophic structure.
Step-by-step explanation:
The ecology includes all the living and non living components of an area. The relationship between the organisms in terms of food, energy and numbers can be indicated by the different pyramids and food chain.
The food chain determines the sequential trophics level of the ecosystem. The organisms eat other organisms and may itself get eaten by other organism is explained by the different trophic levels that includes the different food chain and food web.
Thus, the correct answer is option (a).