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.
Based on the arrows, which of the following organisms is a consumer?
A. Arctic fox
B. lichen
From the given choices, pick the correct answer and respond by indicating the letter of the correct option.

A