1. Tfunction of the eukaryotic DNA replication factor PCNA (proliferating cell nuclear antigen) is similar to that of the β-subunit of bacterial DNA polymerase III in that it:
(A)Participates in DNA repair
(B) Facilitates replication of telomeres
(C) Has a 3'→5' proofreading activity
(D) Increases the speed but not the processivity of the replication complex
(E) Forms a circular sliding clamp to increase the processivity of replication