Context: Below is a food web from a tundra ecosystem in Nunavut, a territory in Northern Canada.
A food web models how the matter eaten by organisms moves through an ecosystem. The arrows in a food web represent how matter moves between organisms in an ecosystem.
Which of the following organisms is the decomposer in this food web?
A. bilberry
B. Arctic fox
C. earthworm
Identify the correct choice from the options below and respond with the letter of the correct option.

C