Question

Phytoplankton are only found at the surface of ocean waters because
A. they feed on tiny organisms living at the surface.

B. they are an important food source to surface-dwelling marine organisms.

C. they require sunlight to carry out photosynthesis.

D. they cannot withstand the colder temperatures of deep water.

Answer 1

c. Phytoplankton require sunlight because they generate energy though photosynthesis.
They do make tasty snacks for the passing aquatic organism, but not purposefully.

Answer 2

thanks Wach