Which one of the following pyramids of biomass is generally inverted…

The correct answer is Option (3) → Sea

Option (1) Forest — Incorrect. In a forest the trees have a huge biomass, far more than the animals that eat them, so the pyramid of biomass is upright.

Option (2) Grassland — Incorrect. The grass has more biomass than the grazers, and the grazers more than the carnivores. The pyramid is upright.

Option (3) Sea — Correct. The producers in the sea are tiny phytoplankton. At any moment their biomass is small, though they multiply fast, while the fishes above them have a much larger biomass.

Option (4) Desert — Incorrect. Plants are few in a desert, but animals are fewer still, so the pyramid of biomass stays upright.

NCERT Extract:
Ecological Pyramids – “… In most ecosystems, all the pyramids, of number, of energy and biomass are upright, i.e., producers are more in number and biomass than the herbivores, and herbivores are more in number and biomass than the carnivores. Also energy at a lower trophic level is always more than at a higher level. There are exceptions to this generalisation: … The pyramid of biomass in sea is generally inverted because the biomass of fishes far exceeds that of phytoplankton.”