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: Pediatrics
[{'content': 'Which of the following is not a feature of hypothyroidism? \nSelect and explain. \nA. Mental retardation, B. Large head, C. Microcephaly, D. Calf muscle hypertrophy', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Hypothyroidism characterized by open and widened fontanelle results in large head and mental retardation', 'role': 'assistant'}]