It starts with a producer and then shows organisms eating other organisms, with arrows flowing in one direction of what eats what. This illustrates a . food chain
food pyramid
food web
pyramids of numbers
trophic pyramids

not sure what exactly it is, but here is some info:

Explanation:

A food web shows what eats what (typically a single line from animal to animal), a food chain shows the whole ecosystem (typically with intersecting lines and a lot of organisms).

answer is a

explanation:

it's c.us forest service