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': 'Which of the following is not seen in Prader Willi syndrome. \nSelect and explain. \nA. Mental retardation, B. Short stature, C. Hypotonia, D. Inappropriate laughter', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Inappropriate laughter is a feature of Angelman syndrome.', 'role': 'assistant'}]