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: Microbiology
[{'content': 'Primary Receptor for Human Immunodeficiency Virus (HIV) is: \nSelect and explain. \nA. CD4, B. CD8, C. CD3, D. CD56', 'role': 'user'}, {'content': 'Answer: A \nExplanation: HIV targets cells that express CD4, and can infect macrophages, dendritic cells (both groups express CD4 at low levels) and CD4+ T cells. Ref: Andrew E. Williams, "Immunology of Urogenital Tract and Conjunctiva", In the book, "Immunology: Mucosal and Body Surface Defences", USA, Wiley Blackwell Publications, Chapter 9.1; Harrison\'s Principles of Internal Medicine, 17th Edition, Pages 1139, 1157; Textbook of Microbiology By Ananthnaraynan, 7th Edition, Page 586', 'role': 'assistant'}]