Which of the following is correct regarding $AIDS$ causative agent $HIV$?

• A
  $HIV$ is an enveloped virus containing one molecule of single-stranded $RNA$ and one molecule of reverse transcriptase.
• B
  $HIV$ is an enveloped virus that contains two identical molecules of single-stranded $RNA$ and two molecules of reverse transcriptase.
• C
  $HIV$ does not escape but attacks the acquired immune response.
• D
  Both $(b)$ and $(c)$.