Your answer is C, DNA Helicase.
DNA helicase is responsible for unzipping the DNA strands during replication, to allow them to be copied.
DNA Polymerase creates new DNA strands by joining nucleotides, sugars, a phosphate groups. It also monitors the base-pairing of the new strand, and proofreads it as well.
DNA ligase seals the gap in the sugar-phosphate backbone, between the lagging strands: short fragments of DNA, called Okazagi fragments.
Hope this helps!
