The given situation in the question where an Adenine nucleotide is swapped for a Thymine nucleotide, which as stated are complimentary of each other just like guanine and cytosine, can cause all three types of mutations, frameshift nonsense, frameshift missense and silent because the situation is not specific to either of them. There is no information whether the change resulted in a change in the amino acid structures or not. In this case the best answer is D.
