In a marine ecosystem,the biomass pyramid is . . . . . . .

Define ecological pyramids and describe with examples,pyramids of number and biomass.

The given figure best represents:

Choose the correct option for the given statements:
($T$ = True,$F$ = False)
$(A)$ Pyramid of energy is always upright.
$(B)$ Pyramid of number in a sea is generally inverted.
$(C)$ Pyramid of biomass in a sea is generally inverted.
$(D)$ In most ecosystems,the pyramid of number and energy are always inverted.

Assertion: Pyramid of energy may be upright or inverted.
Reason: Only $20\%$ of energy goes to the next trophic level.

Which of the following pyramid of numbers in ecology is not upright?