If phytoplanktons are destroyed in the sea,then

Consider the following four statements $(A-D)$ and select the correct option stating which ones are true $(T)$ and which ones are false $(F)$.
Statements:
$(A)$ Vertical distribution of different species occupying different levels in a community is called stratification.
$(B)$ Net primary productivity minus respiration losses is the gross primary productivity.
$(C)$ Rate of biomass production is called decomposition.
$(D)$ Annual net primary productivity of oceans is $55$ billion tons.

Select the correct option from the following.

Find out the correct order of succession levels in xerarch.

Identify the stage of hydrarch succession shown in the figure.

Biological equilibrium is an equilibrium among the