15. Which description about prokaryotic and eukaryotic RNA polymerase is correct?(A) The prokaryotic RNA polymerase consists of 7 subunits. (B) The eukaryotic RNA polymerase consists of 10-20 subunits. (C) The prokaryotic RNA polymerase synthesizes monocistronic RNA. (D) Eukaryotic transcription is regulated by one RNA polymerase. (E) The eukaryotic RNA polymerase synthesizes polycistronic RNA.