This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunology, Subject name: Microbiology
Apa from T & B lymphocytes, the other class of lymphocytes is - 
Select and explain. 
A. Macrophages, B. Astrocytes, C. NK cells, D. Langerhans cells
C: NK cells
Answer: C: NK cells 
Explanation: Lymphocytes include natural killer cells (NK cells) (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adaptive immunity), and B cells (for humoral, antibody-driven adaptive immunity). Reff: Ananthanarayanan & panikers textbook of microbiology 9th edition pg:132