The correct option is C a, b, c, d and e
The cycle of energy is based on the flow of energy through different trophic levels in an ecosystem. the ecosystem is maintained by the cycling energy and nutrients obtained from different external sources. Interaction of biotic and abiotic components result in a physical structure, that is characteristic of each type of ecosystem.
Components of ecosystem function as one single unit. Four important functional aspects of the ecosystem are
(i) Productivity
(ii) Decomposition
(iii) Energy flow
(iv) Nutrient cycling.
Succession is the slow and reasonably predictable shift in the composition of species of a given region.
Stratification is the process of vertical distribution of different species occupying different levels.
So ,the functional components of the ecosystems are :
a. Productivity
b. Decomposition
c. Nutrient cycling
d. Energy flow