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': 'Which of the following virus is oncogenic ? \nSelect and explain. \nA. Arenavirus, B. Retrovirus, C. Reovirus, D. Corona virus.', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. is 'b' i.e., Retrovirus", 'role': 'assistant'}]