Most gaseous pollutants come from a group of chemicals called
a. oxides
b. chlorofluorocarbons
c. ozones
d. hydrocarbons

The correct answer is option A, that is, oxides.  

Air pollution refers to the kind of pollution that takes place because of the discharge of noxious gases, like carbon monoxide, sulfur dioxide, chemical vapors, and nitrogen oxides. These gases can get involved in further chemical reactions once they reach the atmosphere, forming acid rain and smog.  

Air pollution can exhibit various kinds of health associated influences, both long term, and short term.  

1) gene flow

- it is described as the transfer of genes from one population to another population so that frequency of gene is increased.

-a zebra migrates to join a different herd of zebras.

2) natural selection

- a mechanism of evolutionary change in which individuals with advantageous traits survive and reproduce whereas the others ( those that can not adapt) eliminate from the population.

-competition for sunlight leads to taller trees.

3) mutation

- permanent change in the nucleotide sequence of dna ( genetic material) that could have harmful or useful consequences.

-the dna of a snake changes to make its venom stronger.

4) genetic drift - it is a random phenomenon ( that occurs by chance such as fire) that results in change in the gene frequency in a small population.    

-a grassfire randomly sweeps through a population of buffalo and kills most of the animals.

explanation: