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
Which of the following methods is most suitable for isolating gene of long DNA molecules 
Select and explain. 
A. Sanger's sequencing, B. Southern blotting RFCP, C. RFCP, D. Chromosome walking
D: Chromosome walking
Answer: D: Chromosome walking 
Explanation: Chromosome walking is the best method to isolate gene from long segment of DNA.