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': 'Chromosomal abnormality seen in promyelocytic \nSelect and explain. \nA. 17-15t, B. 21-9t, C. 22-9t, D. None of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]