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
Characteristic feature of retrovirus is: 
Select and explain. 
A. Ribonuclease, B. Reverse transcriptase, C. DNA polymerase, D. Restriction endonuclease
B: Reverse transcriptase
Answer: B: Reverse transcriptase 
Explanation: None