Context: Below is a food web from an ocean ecosystem in Monterey Bay, off the coast of California.
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. sea otter
B. kelp
C. plainfin midshipman
D. phytoplankton
Pick the correct answer from the listed options and provide the letter of the selected option.
Answer: C