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: Pediatrics
[{'content': "Predisposing factor for leukemia - \nSelect and explain. \nA. Down syndrome, B. Lowe's syndrome, C. Fragile-x-syndrome, D. None", 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Down syndrome", 'role': 'assistant'}]