This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Immunity, Subject name: Pathology
[{'content': 'Which is a large granular lymphocyte? \nSelect and explain. \nA. NK cell, B. B-lymphocyte, C. T-lymphocyte, D. Macrophage', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. (a) NK cell(Ref: Wintrobe's clinical hematology - 12th ed, pg 300; Robbins 9th/pg 192; 8th/pg 188)Most lymphocytes in blood are small (<=10mm), while some are large, known as large granular lymphocytes (LGL), as they contain azurophilic granules in their cytoplasm.These cells are LGL type of natural killer (NK) cells.", 'role': 'assistant'}]