Why are retroviruses considered a special class of viruses?

a. They leave behind mini-chromosomes when they leave a cell.
b. They carry their own RNA-RNA synthesis enzymes inside their capsids.
c. They transcribe RNA to DNA using reverse transcriptase.
d. They have a phospholipids membrane cloak.
e. They have an RNA genome.

They transcribe RNA to DNA using reverse transcriptase.

Explanation:

Retrovirus

A type of virus that uses RNA as its genetic material. After infecting a cell, a retrovirus uses an enzyme called reverse transcriptase to convert its RNA into DNA. The retrovirus then integrates its viral DNA into the DNA of the host cell, which allows the retrovirus to replicate. HIV, the virus that causes AIDS, is a retrovirus.

Retroviruses have an enzyme, called reverse transcriptase, that gives them the unique property of transcribing their RNA into DNA after entering a cell.

gametes or germ cells are haploid cells (example: sperm and ova) containing only one set (or n) number of chromosomes and autosomal or somatic cells are diploid cells containing 2n number of chromosomes.