Consider the following statements on ecological pyramids and pick out the correct statements:

A) Pyramid of energy can never be inverted, because when energy flows from a particular trophic level to the next trophic level, some energy is always lost as heat at each step.

B) In all ecosystems, the pyramids of number and of biomass are upright.

C) The pyramid of biomass of sea is generally inverted because the biomass of fishes far exceeds that of phytoplankton.