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: Microbiology
[{'content': 'HIV envelop is formed by: \nSelect and explain. \nA. Host cell, B. Virus, C. Both, D. None', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. c. Both', 'role': 'assistant'}]