The correct option is D both (a) and (b)
DNA polymerase I is an enzyme that participates in the process of prokaryotic DNA replication.
DNA Polymerase Ienzyme is a repair polymerase which is involved in excision repair with both 3'-5' and 5'-3' exonuclease activity and processing of Okazaki fragments generated during lagging strand synthesis. Single-strand breaks are repaired by DNA ligase using the complementary strand of the double helix as a template, with DNA ligase creating the final phosphodiester bond to fully repair the DNA. DNA ligase is used in both DNA repair and DNA replication.