Answer:
D. Hepadnaviridae and Retroviridae.
Explanation:
Viruses are the infectious agents which possess the genetic material in the form of RNA or DNA.
The Virus which possess RNA as genetic material is known as the retroviruses as they perform reverse transcriptase activity and form DNA from RNA.
These retroviruses are classified into the group of viruses called the retroviridae and Hepadnaviridae based on the same genetic material and the method of replication mechanism.
Thus, Option-D is correct.
