Which organism in this diagram is a secondary consumer?
phytoplankton
produce half of
the world's oxygen
shrimp feed on
plankton and also
need oxygen to live.
salmon feed on
shrimp and need
oxygen to live.
people often eat
salmon. we also
need to breathe
oxygen to live.

The correct answer will be- Salmon feed on  shrimp and need  oxygen to live.

Explanation:

A food chain is the unidirectional pathway of the flow of energy and matter from one organism to another organism through by eating one another.

The food chain consists of the organism in sequence starting from a producer to primary consumer, secondary consumer and tertiary consumer.

In the marine system, the phytoplanktons are considered producers as they produce their own food through photosynthesis.

The phytoplanktons are eaten by the primary consumers which are shrimp and the shrimp are eaten by the secondary consumer which is salmon in the given case.

Thus, Salmon feed on  shrimp and need  oxygen to live is the correct answer.

b is the best answer for this question.