This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
[{'content': 'CD4 lymphocytes (helper cells) recognize - \nSelect and explain. \nA. HLA class I antigen, B. HLA class II antigen, C. HLA class III antigen, D. None of the above', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Class II MHC antigens have single locus as HLA-D. - these antigens have fuher 3 loci: DR, DQ, and DP. Class II MHC is identified by B cells and CD4+ cells.( T helper cells). ReReference:arsh mohan textbook pathology, 7th edition, pg no:49 <\\p>', 'role': 'assistant'}]