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 RNA virus is ? 
Select and explain. 
A. An leukosis virus, B. Herpesvirus, C. Adenovirus, D. Togavirus
A: An leukosis virus
Answer: A: An leukosis virus 
Explanation: Ans. is 'a' i.e. An leukosis virus