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': 'Philadelphia chromosome is an example of - \nSelect and explain. \nA. Balanced translocation, B. Deletion, C. Non-dysjunction, D. Duplication', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]