This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
[{'content': "Which is not associated with Down's syndrome? \nSelect and explain. \nA. Trisomy 21, B. Mosaic 21, C. Robesonian translocation 21/21,14/21, D. Deletion 21", 'role': 'user'}, {'content': 'Answer: D \nExplanation: .', 'role': 'assistant'}]