The diagram shows the genetic code, which cells use to translate a nucleotide sequence into an amino acid sequence in a protein. Scientists have studied a huge number of species and have found the same genetic code in use among nearly all of them.

A diagram of concentric circles shows the genetic code. The letters A, G, C, and U appear in the center of the diagram, and they are repeated in the next two circles. The outermost circle lists the names of amino acids.

A molecule of mRNA is altered by a point mutation in DNA. Which change to a codon would have the least effect on the protein that is produced?

A. changing UGA to UGU
B. changing UGA to CGA
C. changing UAU to UAG
D. changing UAU to UAC