Answer: B. DNA polymerase checks for errors in base pairing as it helps new DNA strands form.
Explanation: DNA polymerase is an enzyme that catalyzes the synthesis of a new DNA strand from a DNA template. This process is known as replication. During replication, DNA polymerase rejects incorrect bases before the phosphodiester bond is formed because it has a 3' -> 5' exonuclease activity that double checks every nucleotide that is added to the growing strand. This check allows the enzyme to remove a newly added mismatched base pair.
