Answer:
The term "retro" in retrovirus refers to this reversal of the usual direction of transcription.
Step-by-step explanation:
Retroviruses are the viruses from the virus family known as retroviridae. These are the viruses that use RNA as their genetic material and use an enzyme reverse transcriptase which is essential for their life cycle.
they called retro as they use the reverse process of the usual direction of transcription which means from RNA to DNA by duplicated their genetic material to produce DNA and incorporated into the genome of the host.