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 these organisms contains matter that was once part of the lichen?
A. mushroom
B. short-tailed weasel
C. brown lemming
D. rough-legged hawk
E. bilberry
Select the correct answer from the given choices and respond with the letter of the chosen option.
Answer: A