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': "Arnold head is a feature of: \nSelect and explain. \nA. Fibrous dysplasia., B. Paget's disease., C. Cleidocranial dysplasia., D. Cherubim.", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cleidocranial dysplasia is characterized by abnormalities of skull, shoulder girdle, jaws and teeth. In the skull, delayed closing of sutures and wormian bones are common. The characteristic skull abnormalities are sometimes referred to as "Arnold head".', 'role': 'assistant'}]