Answer:
Zooplankton help other populations survive by keeping out other herbivores
Explanation:
This is because a keystone species are species that have large effect on the the habitat and through its effect they help to keep the ecosystem in existence. They make sure that the ecosystem exist. They help populations survive by keeping out herbivores and feeding on the algae. They help drive nutrients cycle and transfer energy from algae to invasive fish.
The layers above would be not as old and the layers below would be the older layers.
The correct answer is C.Acute stressors
