The transfer of energy from one organism to the next in an ecosystem begins with a producer. A producer is an organism that produces its own food. A consumer is an organism in a food chain that obtains energy from producers or other consumers; consumers may be herbivores or carnivores.
Which food chain correctly describes the flow of energy in an ecosystem?

A) grass → grasshopper → fish → human
B) grasshopper → fish → human
C) human → fish → grasshopper
D) human → grasshopper → fish → grass