What type of pyramid of biomass is found in the sea?

$A$: Ecological pyramid of biomass is generally inverted in the sea.
$R$: Biomass of fishes far exceeds that of phytoplanktons.

Consider the following statements about ecological pyramids:
$I.$ Charles Elton developed the concept of ecological pyramid.
$II.$ After his name,these pyramids are also called as Eltonian pyramids.
$III.$ It is a graphical representation or pyramid-shaped diagram which depicts the number of organisms,biomass,and energy at each trophic level.
Which of the statements given above are correct?

What type of ecosystem is represented by the given ecological pyramid?

Identify the correct labels for $a, b,$ and $c$ in the given inverted pyramid.

The pyramid of biomass in the sea is generally inverted because...