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
Most powerful cloning vector ? 
Select and explain. 
A. Plasmid, B. Virus, C. Cosmid, D. Phage
C: Cosmid
Answer: C: Cosmid 
Explanation: Most powerful cloning vector is cosmid as largest DNA can be incorporated in cosmid.Overall, most powerful cloning vector is YAC (Yeast aificial chromosome).