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: Dental
[{'content': 'Haversian systems (osteons) are found primarily in the \nSelect and explain. \nA. Spongy bone, B. Periosteum, C. Alveolar bone proper, D. Endosteum', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]