This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pathology
[{'content': 'ALL L3 morphology is a malignancy arising from which cell lineage - \nSelect and explain. \nA. Mature B cell, B. Precursor B cell, C. Immature T cell, D. Mixed B cell & T cell', 'role': 'user'}, {'content': 'Answer: A \nExplanation: • Acute Lymphoblastic Leukemias (ALL) of the L3 (FAB) subtype are tumors of Mature B-cells (e.g. Burkitt’s lymphoma)', 'role': 'assistant'}]