The best answer is option D.
Acid rain is simply rainfall that has been rendered acidic due to water vapor reacting with nitrogen oxide ad sulphur dioxide very high up in the atmosphere.
Acid rain is not only a threat to the ecosystem and environment, but also seriously damages buildings and sculptures.
Marble and limestone are especially vulnerable to acid rain. This is because the two building or construction materials contain calcite which is easily dissolved by acid.
Concrete surfaces and paint finishes are also seriously damaged by acid rain.
I think that that the answer should be C asexual reproduction of a single-celled organism
Lichens and algae I believe
Greenhouse is due to excess of CO2 , Methane gas !! It has both benefits and demerits !!
