49. The function of the eukaryotic DNA replication factor PCNA (proliferating cell nuclear antigen) is similar to that ofthe ẞ-subunit of bacterial (A) DNA polymerase III in that it: facilitates replication of telomeres. (B) forms a circular sliding clamp to 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.