12. The function of the eukaryotic DNA replication factor PCNA (proliferating cell nuclear antigen) is similar to that of the B-subunit of bacterial DNA polymerase III in that it: (A)facilitates replication of telomeres. (B)increase the processivity of replication. (C)has a 3' → 5' proofreading activity. (D)increases the speed but not the processivity of the replication complex. (E)participates in DNA repair.