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
Which of the following virus is oncogenic ? 
Select and explain. 
A. Arenavirus, B. Retrovirus, C. Reovirus, D. Corona virus.
B: Retrovirus
Answer: B: Retrovirus 
Explanation: Ans. is 'b' i.e., Retrovirus