The correct option is
C Single stranded RNA virus
AIDS stands for acquired immune deficiency syndrome. It is caused by HIV (human immunodeficiency virus) virus. It belongs from the retroviridae family. These are also known as a retrovirus. It is an RNA virus and it is single-stranded. It uses RNA dependent DNA polymerase (reverse transcriptase) to replicate into DNA.
Thus, the correct answer is 'Single-stranded RNA virus.'