On average, errors occur in dna synthesis only once in every ten billion nucleotides incorporated. which of the following does not contribute to this high fidelity of dna synthesis? (a) complementary base-pairing between the nucleotides (b) tightening of the dna polymerase around its active site to ensure correct pairing before monomer incorporation (c) proofreading by the 3'-to-5' exonuclease activity of the enzyme to correct mispairing even after monomer incorporation (d) a strand-directed mismatch repair system that detects and resolves mismatches soon after dna replication (e) none of the above