Question

what does a cytotoxic t cell look for in order to destroy an infected cell?
the mhc 1 holding a piece of the antibody that is infecting the body cell.
the mhc 2 holding a piece of the antigen that is infecting the body cell.
the mhc 2 holding a piece of the antibody that is infecting the body cell.
the mhc 1 holding a piece of the antigen that is infecting the body cell.

Explanation:

Cytotoxic T cells recognize infected cells by binding to MHC class I molecules, which are present on all nucleated body cells. These MHC I molecules display fragments of intracellular antigens (from pathogens infecting the cell) on the cell surface. MHC II is primarily used by antigen-presenting cells to activate helper T cells, not cytotoxic T cells. Antibodies are produced by B cells, not displayed by MHC molecules to target infected cells for cytotoxic T cells.

Answer:

The MHC 1 holding a piece of the antigen that is infecting the body cell.