The statement that BEST explains the outcome is:
Different codons can be translated into the same amino acid, so some mutations do not affect protein synthesis.
This phenomenon is known as the redundancy or degeneracy of the genetic code, where multiple codons can encode for the same amino acid. As a result, certain mutations (like silent mutations) do not change the amino acid sequence of the resulting protein, leading to the same functional protein despite the mutation occurring in the DNA sequence.