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': 'Not a B cell lymphoma - \nSelect and explain. \nA. Mycosis fungoides, B. CLL, C. Hairy cell leukemia, D. Mantle cell lymphoma', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Mycosis fungoides is a slowly evolving cutaneous T-cell lymphoma occuring in middle aged adult males Ref: Harshmohan textbook of pathology pg:359', 'role': 'assistant'}]