Answer:
The correct option is D. Helicase is the enzyme that unwinds that double stranded DNA at the beginning of DNA replication.
Step-by-step explanation:
DNA replication can be described as a process by which the strand of DNA gets duplicated into two new daughter strands.
Helicases can be described as the enzymes whose main function is to unwind the double helix structure of the DNA. The helicases break the hydrogen bonds present between the two strands of DNA. The helicases are the first machinery for DNA replication as they form the replication fork and begin unwinding of the DNA from the origin of replication