AIDS is caused by:

Explanation

Option B is correct. Yes, AIDS is caused by a virus. The virus is called the human immunodeficiency virus (HIV). HIV is a retrovirus, which means that it carries its genetic material in the form of RNA. The RNA is reverse transcribed into DNA by the virus's reverse transcriptase enzyme. The DNA is then integrated into the DNA of the host cell, where it can be replicated and transcribed into new viral RNA. It is not caused by bacteria, fungi, or algae.