D) A mutation can lead to the incorrect synthesis of proteins, which play a fundamental role in regulating cell activities.
Proteins are crucial to organisms as they regulate many of the cell's activities. Protein synthesis relies on DNA because DNA codes for the mRNA that is read by the ribosomes, and the ribosomes are what produce the proteins. A mutation can cause the incorrect amino acid to be coded for, which can affect the protein that the amino acid sequence/polypeptides create,