RNA polymerase enzyme catalyses the synthesis of RNA. It is single in prokaryotes. There are three types of RNA polymerases in eukaryotes-I for 28S, 18S and 5.8S RNA, II for mRNA and snRNA and III for tRNA, 5SRNA and ScRNA. Primase is an RNA polymerase that is used to initiate DNA synthesis. RNA ligase reunites the exon segment after RNA splicing. So, correct answer is RNA ligase