This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Structure and function of protein, Subject name: Biochemistry
Function of Topoisomerases 
Select and explain. 
A. Deoxynucleotide polymerization, B. Relieve torsional strain, C. Initiates synthesis of RNA primers, D. Prevent premature reannealing of dsDNA
B: Relieve torsional strain
Answer: B: Relieve torsional strain 
Explanation: Classes of Proteins Involved in ReplicationProteinFunctionDNA polymerasesDeoxynucleotide polymerizationHelicasesATP -driven processive unwinding of DNATopoisomerasesRelieve torsional strain that results fromhelicase-induced unwindingDNA primaseInitiates synthesis of RNA primersSingle-strand bindingproteins (SSBs)Prevent premature reannealing of dsDNADNA ligaseSeals the single strand nick between thenascent chain and Okazaki fragments on the lagging strandRef: Harper&;s Biochemistry; 30th edition; Chapter 35; DNA Organization, Replication, & Repair