Base substitution mutations can have the following molecular consequence, EXCEPT:: (A) Changes one codon for an amino acid into another codon for that same amino acid, (B) Codon for one amino acid is changed into a codon of another amino acid, (C) Reading frame changes downstream to the mutation site, (D) Codon for one amino acid is changed into a translation termination codon
Answer is C. Reading frame changes downstream to the mutation site occurs in frameshift mutations but not in base substitution mutations. Ref: Harper Illustrated Biochemistry, 26th Edition, Chapter 38, Pages 361-64