This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of nucleic acids, Subject name: Biochemistry
The enzyme responsible for unwinding of DNA is 
Select and explain. 
A. DNA Ligase, B. Helicase, C. DNA primase, D. Topoisomerases
B: Helicase
Answer: B: Helicase 
Explanation: Classes of Proteins Involved in Replication Protein Function DNA polymerases Deoxynucleotide polymerization Helicases ATP -driven processive unwinding of DNA Topoisomerases Relieve torsional strain that results from helicase-induced unwinding DNA primase Initiates synthesis of RNA primers Single-strand binding proteins (SSBs) Prevent premature reannealing of dsDNA DNA ligase Seals the single strand nick between the nascent chain and Okazaki fragments on lagging strand Harper30e pg: 378