<u>My work:</u> Acid rain is a big pollution. Acid rain is caused by smoke in a rain cloud do to pollution from smock factories.This make A correct, because even if though Sewage treatment plants clean pollution they produce pollution from there plants.
Explanation: If you have a dominant allele it will show in the phenotype of the organism. To show a recessive allele you need a recessive pair consisting of only recessive alleles