Select the pathway that would lead to the activation of cytotoxic t cells.

The pathway will be;
The body cells becomes infected with a virus= then new viral proteins appear = class I MHC molecule-antigen complex displayed on cell surface. 
Cytotoxic T cell is a T lymphocyte that kills cancer cells, cells that are infected or cells that are damaged in other ways. They are activated on the surface of antigen-presenting cells, which mature during the innate immune responses triggered by an infection.

The last option water because it is slow