This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Specific Cytogenetic Disorders, Subject name: Pathology
[{'content': 'Which of the following is the most common hematological malignancy in children with Down syndrome? \nSelect and explain. \nA. T-cell acute lymphoblastic leukemia, B. Burkitt leukemia, C. Acute promyelocytic leukemia, D. Acute megakaryoblastic leukemia', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Children with trisomy 21 have a high risk of developing leukemia. There is 20-fold increased risk of developing acute B lymphoblastic leukemias. There is 500-fold increased risk of acute myeloid leukemias, most commonly, acute megakaryoblastic leukemia.', 'role': 'assistant'}]