This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Haematology, Subject name: Pathology
[{'content': 'All of the following NHL involve the white pulp of spleen Except \nSelect and explain. \nA. Hairy cell leukemia, B. Burkitt lymphoma, C. Follicular lymphoma, D. Mantle cell lymphoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hairy cell leukemia is a rare, slow-growing cancer of the blood in which your bone marrow makes too many B cells (lymphocytes), a type of white blood cell that fights infection. These excess B cells are abnormal and look "hairy" under a microscope.', 'role': 'assistant'}]