This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Biochemistry
The gaps between segments of DNA on the lagging strand produced by restriction enzymes are rejoined sealed by: 
Select and explain. 
A. DNA Ligases, B. DNA Helicase, C. DNA topoisomerase, D. DNA phosphorylase
A: DNA Ligases
Answer: A: DNA Ligases 
Explanation: A i.e. DNA Ligases