This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Virology, Subject name: Microbiology
[{'content': 'HIV affects - \nSelect and explain. \nA. Only T helper cells, B. T helper and macrophages, C. NK cells, D. B-lymphocytes', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Receptor for the virus is CD4 antigen and affect the cells with this receptor like CD4 T cell, macrophages, monocytes. REF:Textbook of microbiology, Ananthanarayan and Paniker. Page no.: 574', 'role': 'assistant'}]