Answer
b. the ocean photic zone.
Work Step by Step
Phytoplankton need light to survive. These organisms, like green plants that live on land, contain chlorophyll and make their own food through the process of photosynthesis, which needs the presence of sunlight. Phytoplankton normally float near the surface of oceans and lakes so that they can make use of the sunlight that is abundant there. They cannot live in deeper areas because sunlight can only penetrate the upper portions of oceans and lakes.
