A Mutation Has Occurred During DNA Replication While the Cell

Multiple Choice

A mutation has occurred during DNA replication while the cell was preparing to divide.As a result of this, the codon ACU of mRNA has now become ACC.Interestingly, there is no change to the protein being made.Why not?

A) This is a silent mutation.
B) The original amino acid isoleucine was changed to leucine, but they are the same variation of amino acid so no change to the protein.
C) The mutation was fixed, and even though the codon is now ACC the correct amino acid is put into place for the normal protein.
D) This is not a mutation that causes a big change, so there is no change to the protein being made.