Answer:
(c). frameshift mutation.
Explanation:
Mutations are permanent changes in the DNA due to changes in nucleotide sequences. Mutations that cause addition of extra nucleotides in a nucleotide sequences are known as frameshift mutations.
This is because they lead to change in open-reading frames or translational reading frames and change the entire amino acid sequence coded by rest of the gene.
Thus, the correct answer is option (c).
