Look at the ocean system below.

plankton → shrimp → salmon → humans

What will most likely happen if the plankton population decreases in this

ocean system?

All the other animals that depend on it will go down

Explanation:

Then all the animals will be fighting over food and then it will become survival of the fittest

The correct answer is "the population of shrimp, salmon and humans will also decrease".

Explanation:

Plankton is one of the most important producers in the world, is the ocean's primary producers and most of the species depend on them. Under the simple ocean system stated in the question, if the plankton population decreases the population of shrimp, salmon and humans will also decrease. At first, the decrease in plankton population will affect shrimp's population, which in consequence will affect the salmon and humans populations.