Final answer:
CD8+ T cells do not use oxidative burst as a mechanism of killing; they instead utilize granzyme, perforin, and Fas-induced apoptosis.
Step-by-step explanation:
The mechanism of killing that is not used by CD8+ T cells (also known as cytotoxic T cells) is b. oxidative burst. The CD8+ T cells utilize a variety of mechanisms to induce apoptosis in target cells, including granzyme and perforin release, as well as Fas-induced apoptosis. Granzyme is a protease that enters target cells through pores formed by perforin and induces apoptosis. Fas ligand molecule is expressed on cytotoxic T cells and NK cells that binds to the Fas molecule on a target cell, leading to apoptosis. In contrast, the oxidative burst is an antimicrobial mechanism used by phagocytes such as neutrophils and macrophages, rather than by cytotoxic T cells.