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 proof reading and repair is done by 
Select and explain. 
A. DNA polymerase, B. DNA ligase, C. DNA gyrase, D. DNA primase
A: DNA polymerase
Answer: A: DNA polymerase 
Explanation: DNA Polymerases Ecoli Eukaryotic Function I Gap filling following DNA replication, repair, and recombination II DNA proofreading and repair b DNA repair g Mitochondrial DNA synthesis III e Processive, leading strand synthesis a Primase d Processive, lagging strand synthesis Harper30e pg: 383