Context: Below is a food web from Shenandoah National Park, a forest ecosystem in Virginia.
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 primary consumer in this food web?
A. bobcat
B. pine vole
C. silver maple
D. black racer
From the given choices, pick the correct answer and respond by indicating the letter of the correct option.

B