Answer: C) It increases genetic diversity by introducing new alleles
Explanation: A mutation is an alteration to a genetic sequence of an individual. This can occur because nucleotides are added, deleted, substituted, or a mix of all 3 can occur at once within a DNA sequence. Nonetheless, mutations introduce new alleles and genetic sequences into the genome, thereby increasing genetic diversity within a population.
Choices A, B, and D are all incorrect because mutations do indeed have an effect on genetic diversity but increase genetic diversity rather than decrease it. This is because mutations introduce new nucleotide sequences that can result in new traits and adaptations, thus increasing diversity within a species.