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': "A hair on end appearance of the skull is seen in all of the following expect \nSelect and explain. \nA. Thalassemia, B. Sickle anemia, C. Cooley's anaemia, D. Pagets disease", 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]