This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Medicine
[{'content': 'The following feature is common to both cytotoxic T cells and NK cells? \nSelect and explain. \nA. Synthesizes antibodies, B. Require antibodies to be present for action, C. Effective against virus infected cells, D. Recognize antigen in association with HLA class II markers', 'role': 'user'}, {'content': "Answer: C \nExplanation: Common to both cytotoxic T cells and NK cells is affectivity against virus-infected cellsNK cells:1st line of defense against virus-laden cells and neoplastic cellsCytotoxicity is not MHC restricted Cytotoxic T cells:They are antigen-specific T cells whose function is to produce antigen-specific lysis of target cells by the direct cell to cell contactAre usually CD+ class I MHC restricted T cellsAre impoant in defense against virus infections of tissues (Ref: Harrison's 18/e p2688,2669)", 'role': 'assistant'}]