In Tidal Pools,a Food Pyramid Is Inverted with a Small

In tidal pools,a food pyramid is inverted with a small base of phytoplankton supporting zooplankton consumers.How can this be explained?

A) The pyramid is an energy pyramid and the trophic level occupied by zooplankton contains more energy than the level occupied by phytoplankton.
B) The pyramid is a numbers pyramid showing that only few phytoplankton support many zooplankton.
C) These phytoplankton are actually deriving their food from dying animals,thus the pyramid is inverted.
D) The pyramid is a pyramid of biomass and the standing crop of phytoplankton has less biomass than the standing crop of zooplankton.