Which virus is given as an example of a retrovirus?

• A. HIV
• B. Influenza A virus
• C. Herpes simplex virus
• D. Rhinovirus

Answer: (A)

The key idea is that retroviruses carry reverse transcriptase and reverse-transcribe their RNA genome into DNA, which then integrates into the host cell’s DNA to drive viral replication. This is why HIV is the best example: it uses reverse transcriptase to convert its RNA into DNA, and this DNA becomes a provirus that can persist and continually produce new virus particles.

In contrast, the other viruses listed do not reverse-transcribe their genomes. Influenza A is a negative-sense RNA virus that replicates its RNA in the nucleus but does not produce DNA from RNA. Herpes simplex is a DNA virus, not RNA-based, and rhinovirus is a small positive-sense RNA virus—neither uses reverse transcription.