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
Oncogenic DNA virus is ? 
Select and explain. 
A. Retrovirus, B. HBV, C. HIV, D. HTLV
B: HBV
Answer: B: HBV 
Explanation: Ans. is 'b' i.e., HBV