Cytotoxic T cells induced by infection with virus A will kill target cells:

  •   Infected with a different virus and identical at class I MHC loci of the cytotoxic cells
  •   Infected by virus A and identical at class II MHC loci of the cytotoxic T cells
  •  Infected by virus A and identical at class I MHC loci of the cytotoxic T cells
  •   From the same host infected with any virus
  •   Infected with a different virus and identical at class II MHC loci of the cytotoxic cells