In the context of DNA repair and replication fidelity, how does DNA polymerase help prevent mutations during DNA synthesis?

• A. By proofreading newly added nucleotides using its $3\prime$ to $5\prime$ exonuclease activity to remove mismatched bases
• B. By directly reversing UV-induced thymine dimers through photoreactivation
• C. By methylating mismatched bases to mark them for replacement by mismatch repair proteins
• D. By excising bulky DNA adducts using nucleotide excision repair endonucleases

Answer: (A)