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 secondary consumer in this food web?
A. persimmon tree
B. swallowtail caterpillar
C. beaver
D. black racer
From the given choices, choose the correct answer and respond with the letter of that choice.

D