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
[{'content': 'In gene cloning, largest fragment can be incorporated in - \nSelect and explain. \nA. Plasmid, B. Bacteriophage, C. Cosmid, D. Retrovirus', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]