The pyramid of numbers becomes partly inverted and partly erect for which of the following?

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.

Which of the following statements is true?

Which ecosystem has the maximum number of producers per unit area?

In an ecosystem,what do the pyramid of numbers,pyramid of biomass,and pyramid of energy represent respectively?

The pyramid of energy is always: