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': "In Down's syndrome - \nSelect and explain. \nA. Gap (sandle gap), B. Cliodactyly, C. Hypotonia, D. All", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]