What is the correct sequence in a hydrosere (hydrarch succession)?

$Mr. X$ is eating curd. What is his trophic level in the food chain for this food?

Arrange the stages of hydrarch succession in the correct sequence.

If a sparrow feeds on insects and worms,it is included in which of the following trophic levels?

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.

Identify the likely organisms $(1), (2), (3)$ and $(4)$ in the food web shown below.