Answer:
Krill
Explanation:
If you look at the diagram for this assignment, you can see the main organism that produces its own food is the phytoplankton. The animal that eats that organism is called a primary consumer. So, if you were to follow the arrow from the phytoplankton (or the producer), it would lead you to the zooplankton, krill, and cod. Since there are only one of these primary consumers as the choices, you would pick the only one available for the multiple choice, which would be krill :D
