This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
[{'content': 'HIV virus has : \nSelect and explain. \nA. Single  stranded  DNA, B. Single  stranded  RNA, C. Double  stranded  DNA, D. Double  stranded  RNA', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Classification of HIV ( = HTLV III) \nFamily – Retroviridae\nSubfamily – Lentivirus\nGenome – SS RNA positive sense.\n• Virion contain lipoprotein envelope and nucleocapsid is icosahedral in shape.\n• Characteristic feature of retrovirus is presence of reverse transcriptase enzyme.\n– Viral RNA is transcribed by this enzyme first into SS DNA then to ds DNA which gets integrated with\xa0host cell.\n– Thus in contrast to central dogma flow of information is RNA\xa0 →\xa0 DNA\xa0 →\xa0 RNA', 'role': 'assistant'}]