Answer:
D) secrete a cytokine that triggers apoptosis
Explanation:
Cytotoxic T cells also known as killer cells are lymphocytes that can kill foreign cells (also cancer cells, damaged and infected cells). They express specific type of receptors called T-cell receptors (TCRs) which recognize antigen of foreign cells. Cytotoxic T cells release cytotoxins such as perforin and granzymes and their role is to trigger the signal cascade in the target cell that will lead to apopotsis.