This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Human Immunodeficiency Virus, Subject name: Microbiology
[{'content': 'Following is the marker of HIV infection in blood: \nSelect and explain. \nA. Reverse transcriptase, B. DNA polymerase, C. RNA polymerase, D. None', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a', i.e., Reverse transcriptase(Ref: Harrison, 18th/e, p. 1539, 1540; 19th/e, p. 1219)* Plasma level HIV RNA can be measured by reverse - transcriptase polymerase chain reaction (RT - PCR) or branched DNA assay (b DNA).* Other markers of HIV infection:-p24 antigen.-Double stranded DNA.", 'role': 'assistant'}]