Which virus is known to enter a host cell and change its RNA to DNA?

The Human Immunodeficiency Virus (HIV) is known for its ability to enter a host cell and convert its RNA into DNA through a process called reverse transcription. This unique characteristic is essential for the life cycle of retroviruses, the family to which HIV belongs. Once HIV enters the host's immune cells, specifically the CD4+ T cells, its viral RNA genome is reverse-transcribed into complementary DNA (cDNA) using the viral enzyme reverse transcriptase. This newly formed DNA is then integrated into the host's genome, allowing the virus to replicate and produce new viral particles.

In contrast, the other viruses listed, like Hepatitis A, Hepatitis B, and Hepatitis C, do not utilize this reverse transcription mechanism. Hepatitis B, though it does involve DNA, is classified differently; it has a unique replication strategy involving both DNA and RNA but does not undergo the same reverse transcription as HIV. This distinction clarifies why the Human Immunodeficiency Virus is specifically recognized for its ability to alter RNA into DNA upon entering a host cell.