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: Medicine
Cytotoxic T cells induced by infection with virus A will kill target cells 
Select and explain. 
A. From the same host infected with any virus, B. Infected by virus A and identical at class I MHC loci to the cytotoxic T cells, C. Infected by virus A and identical at class II MHC loci to the cytotoxic T cells, D. Infected with any virus and identical at class I MHC loci to the cytotoxic cells
B: Infected by virus A and identical at class I MHC loci to the cytotoxic T cells
Answer: B: Infected by virus A and identical at class I MHC loci to the cytotoxic T cells 
Explanation: The CD8+ cytotoxic T cells have antigen specific T-cell receptors (TCR) on their membranes that will recognize and bind to self class I antigens. Since the viral peptides are presented as a complex with the self class I antigens, the CD8+ cells can now recognize and react to the virus A peptides. Remember that class I antigens are expressed on all nucleated cells and platelets. Ref: Levinson W. (2012). Chapter 58. Cellular Basis of the Immune Response. In W. Levinson (Ed), Review of Medical Microbiology & Immunology, 12e.