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
[{'content': 'Components of Innate immunity that are active against viral cells includes - \nSelect and explain. \nA. NK cells, B. Cytotoxic cells, C. B-cell, D. Memory B cell', 'role': 'user'}, {'content': "Answer: A \nExplanation: A class of lymphocytes called natural killer cells or NK cells are impoant in nonspecific defense against viral infections and tumors. They selectively kill virus-infected cells and tumors cells. - they are activated by interferons. Reference : Anathanarayan & paniker's 9th edition, pg no:81 <\\p>", 'role': 'assistant'}]