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
DNA repair proofreading in prokaryotes are caused by 
Select and explain. 
A. DNA Polymerase I, B. DNA Polymerase II, C. DNA Polymerase III, D. Gyrase
B: DNA Polymerase II
Answer: B: DNA Polymerase II 
Explanation: The in vivo functionality of Pol II is under debate, yet consensus shows that Pol II is primarily involved as a backup enzyme in prokaryotic DNA replication.The enzyme has 5' - 3' DNA synthesis capability as well as 3' - 5' exonuclease proofreading activity.DNA Pol II interacts with multiple binding paners common with DNA Pol III in order to enhance its fidelity