7. Select the pathway that would lead to the activation of cytotoxic T cells. (A) B cell contact antigen → helper T cell is activated → clonal selection occurs (B) body cell becomes infected with a virus → new viral proteins appear → class I MHC molecule-antigen complex displayed on cell surface (C) complement is secreted → B cell contacts antigen → helper T cell activated → cytokines released (D) cytotoxic T cells → class II MHC molecule-antigen complex displayed → cytokines released → cell lysis