If forest area is reduced to half, which one of the following will be a long term effect

$A$ : Detrivores and decomposers hold up a part of nutrients contained in detritus.

$R$ : Immobilised nutrients cannot be available for solubilisation after the death of saprotrophs.

In an ecosystem, there is flow of energy at different trophic levels. This is as follows :

Which one of the following is a correct food chain

Transfer of energy from one trophic level to other trophic level is according to the second law of thermodynamics. The efficiency of energy transfer from herbivorous to carnivorous is