This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Replication, Subject name: Biochemistry
[{'content': 'During unwinding of DNA, relief of supercoil is made possible by \nSelect and explain. \nA. Topoisomerase, B. Gyrase, C. Helicase, D. Polymerase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: During unwinding of DNA, relief of supercoil is made possible by Topoisomerase DNA helicase unwinds the DNA without cutting but using energy from hydrolysis of ATP. Gyrase is a bacterial type II topoisomerase which acts on closed circular DNA (bacteria have circular DNA).', 'role': 'assistant'}]