Which of the following describes a silent mutation?

A silent mutation occurs when a change in the DNA sequence does not alter the amino acid sequence of the resulting protein. This typically happens when the mutation occurs in a codon that codes for the same amino acid due to the redundancy in the genetic code, where multiple codons can code for the same amino acid. For example, if the original sequence is GGC, which codes for glycine, a mutation to GGU would still code for glycine, resulting in no change to the protein being synthesized.

The nature of silent mutations means they often have no observable effect on an organism's phenotype, though they can still occur within the genetic material. This is a crucial distinction from other types of mutations, like missense mutations, which change one amino acid in a protein, or nonsense mutations, which introduce a premature stop codon, truncating the protein.

Moreover, regulatory sequence mutations can influence gene expression but do not typically fit the definition of a silent mutation, which specifically refers to changes within coding sequences that leave the amino acid sequence unchanged. Thus, the correct answer emphasizes the feature of silent mutations that is fundamental to understanding genetic variations and their effects on proteins.