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: Pathology
MHC antigens are absent on? 
Select and explain. 
A. Platelet, B. Erythrocyte, C. Neutrophil, D. Monocyte
B: Erythrocyte
Answer: B: Erythrocyte 
Explanation: Ans: B. Erythrocyte(Ref: Ananthanarayan 10/e p141-143, 8/e p 132-135)MHC antigens:Absent on erythrocytes.HLA antigens:Class 1 antigens (A, B and C) - Found on surface of viually all nucleated cells.Principal antigens.Involved in graft rejection & cell-mediated cytolysis.Function as components of hormone receptors.HLA class II antigens:More restricted in distribution.Found only on cells of immune system-macrophages, dendritic cell activated T cells & mainly on B cells.