The genetic material of retroviruses (AIDS virus) is:

Explanation

The genetic material of retroviruses, including the AIDS-causing Human Immunodeficiency Virus (HIV), is single-stranded RNA (ssRNA). Unlike most viruses, retroviruses use a special enzyme called reverse transcriptase to convert their RNA into DNA once inside the host cell. This viral DNA then integrates into the host's genome, allowing the virus to replicate using the host's cellular machinery. This unique replication strategy is a key feature of retroviruses and is central to the persistence and progression of HIV infection.