The environment performs four vital functions (i) it supplies resources: resources here include both renewable and non-renewable resources. (ii) it assimilates waste (iii) it sustains life by providing genetic and bio diversity and (iv) it also provides aesthetic services like scenery etc. The environment is able to perform these functions without any interruption as long as the demand on these functions is within its carrying capacity. This implies that the resource extraction is not above the rate of regeneration of the resource and the wastes generated are within the assimilating capacity of the environment.
Absorptive capacity means the ability of the environment to absorb degradation.

All 1, 2 and 3 are correct.
Species of Pseudomonas, Mycobacterium, Haemophilus, Rhodococcus, Paenibacillus and Ralstonia, are some of the most extensively studied bacteria for their bioremediation capability.
Nitrosomonas are also useful in bioremediation.

Option c is correct.
Production/unit area depends on the number and diversity of producers.
Mangroves are one of the high productive regions in the world whereas ocean has least productivity.

All 1, 2 and 3 are correct.
Black carbon consists of pure carbon in several linked forms formed through the incomplete combustion of fossil fuels, biofuel, and biomass, and is emitted in both anthropogenic and naturally occurring soot.
As BC particles absorb heat, they warm the surrounding air, become lighter and rise to greater heights by a process called self-lift and persist in the air.
Because BC particles strongly absorb solar and terrestrial radiation and heats up the atmosphere it can upset the monsoon system. If deposited on snow, it could accelerate the heating of snow and quicken the melting of glaciers.
BC is a short-lived climate pollutant.

Both 1 and 2 are correct.
Fly ash is a byproduct from burning pulverized coal in electric power generating plants. Fly ash contains trace concentrations of heavy metals and other substances that are known to be detrimental to health. Ash that is stored or deposited outdoors can eventually leach toxic compounds into underground water aquifers. Fly ash contains crystalline silica which is known to cause lung disease, in particular silicosis.