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: Medicine
[{'content': 'Bad prognosis in AML is indicated by - \nSelect and explain. \nA. Monosomy, B. Deletion of X or Y chromosome, C. T(8:21), D. Nucleophosmin mutation', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]