Choose best statement that describe this group of zooplankton These are not zooplankton but actually photosynthetic phytoplankton These are multicellular protists (protozoa) that form carbonate shells (radiolaria) and opal shells (foraminifera) These are multicellular crustaceans (copepods) that feed on large phytoplankton and zooplankton These are unicellular protists (protozoa) that form carbonate shells (foraminifera) and opal shells (radiolaria).