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': "Osteitis fibrosa cystica refers to: \nSelect and explain. \nA. Paget's disease., B. Fibrous dysplasia., C. Hyperparathyroidism., D. Osteogenesis imperfecta.", 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]