The nonsense mutation can be defined as the mutation which arises when a sense codon is changed to a terminating one because of the mutation. A missense mutation can be defined as the mutation when a single nucleotide change leads to the formation of a codon coding for a different amino acid. The frame-shift mutation refers to the addition or deletion of a codon that changes the reading frame of the codons. The silent mutation refers to the mutation, which does not cause any change in the synthesized proteins from the altered codon.
In the question, the same protein is being synthesized even after the mutation. Hence, the correct answer is 'silent mutation'.