Identify the incorrect statement about antigen presentation.

• A. Dendritic cells, macrophages, and B cells are examples of antigen presenting cells.
• B. MHC class II are expressed only by antigen presenting cells.
• C. Most nucleated cells display antigens at cell surface using MHC class I protein.
• D. MHC classes I and II present antigen to helper T and cytotoxic T cells, respectively.

Answer: (D)