This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Lymphocytic Leukemia, Subject name: Pathology
[{'content': 'Examination of a peripheral blood smear demonstrates leukemia composed of small mature lymphocytes without blast forms. Which of the following is the most likely age of this patient? \nSelect and explain. \nA. 1 year, B. 20 years, C. 45 years, D. 65 years', 'role': 'user'}, {'content': 'Answer: D \nExplanation: The disease described is chronic lymphocytic leukemia (CLL), which is a disease of older adults. The 1 year-old (choice A) would be most likely to have acute lymphocytic leukemia (ALL). The 45 year-old (choice C) would be likely to have either AML or chronic myelogenous leukemia (CML).', 'role': 'assistant'}]