How are natural killer cells able to kill infected host cells?

• A. NK cells bind to IgG antibodies on the infected cell’s surface and send apoptosis signals to the infected cell.
• B. NK cells send perforin and protease granules to the infected cell triggering apoptosis of the infected cell.
• C. NK cells bind to antigens on the infected cell’s surface and send signals triggering apoptosis of the infected cell.
• D. NK cells mark infected cells for destruction and the infected cell will later be destroyed by cytotoxic T cells.
• E. A and B.
• F. C and D.
• G. D only.
• H. All of the above.