Answer:
The correct answer will be option-B.
Explanation:
Viral polymerases are the enzymes which play an important role in the viral genome transcription and replication.
Retrovirus is the single-stranded RNA viruses which replicate through a DNA intermediate and therefore requires the RNA-dependent DNA polymerase or reverse transcriptase. Reverse transcriptase encodes DNA from the strand of RNA which can be replicated and helps in the reproduction of the virus.
Thus, option- B is the correct answer.