<span>The correct answer is B. Insertion. In this particular insertion there is an insert of three bases. Complementary strands in DNA are the opposite strand, so Adenine is coupled to Thymine and Guanine is coupled to Cytosine. So the complementary sequence (also called the antisense strand) of the original would be GTC GGC ATC, there's an extra 3 bases in there: ACA.</span>
Aquatic environments, mainly the sea.