Helicase move along the double-stranded DNA and separate the strands by breaking hydrogen bonds, using from ATP. DNA ligase enzyme joins two Okazaki fragments together via phosphodiester bond between 3' hydroxyl at the end of one fragment and a 5' phosphate at the end of another fragment. DNA polymerase I serve clean-up functions during replication, recombination, and repair. It has 3' to 5' proofreading exonuclease activity and 5' to 3' exonuclease activity. The 5' to 3' exonuclease activity of DNA polymerase I can replace an error containing the segment of DNA/RNA, paired to the template strand which is then simultaneously replaced by polymerase activity of the same enzyme. Primase synthesizes RNA/DNA primer which is a stranded segment (complementary to the template) and has a free 3’ -hydroxyl group to facilitate the addition of nucleotides by polymerase enzymes. RNA polymerase synthesizes RNA using DNA template strand by adding the ribonucleotides to a primer in 5' to 3' direction via phosphodiester bonds. The correct answer is B.