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
Components of innate immunity are - 
Select and explain. 
A. T lymphocytes, B. Complement proteins, C. B lymphocytes, D. NK cells
D: NK cells
Answer: D: NK cells 
Explanation: Natural killer cells (NK cells) are a component of the innate immune system that does not directly attack invading microbes. Other components are mast cells, eosinophils, basophils; and the phagocytic cells including macrophages, neutrophils, and dendritic cells. Ref: Ananthanarayan & Panikers textbook of microbiology 9th edition pg.no. : 78-81