The correct option is A AIDS is an immunodeficiency disease
AIDS (Acquired Immuno Deficiency Syndrome) is caused by HIV. This virus selectively infects and kills the T-lymphocytes. The first step post infection is the reverse transcription of RNA into DNA so that this r-DNA can get inserted into the human genome. This is brought about by a viral enzyme, known as HIV-RT, in which RT stands for reverse transcriptase. There is a class of drugs called Antiretroviral drugs (ARV) which are essentially inhibitors of this enzyme.