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 producer?
A. lichen
B. barren-ground caribou
Identify the correct choice from the options below and respond with the letter of the correct option.
Answer: A