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: Orthopaedics
[{'content': 'True about osteoporosis \nSelect and explain. \nA. Normal serum calcium levels, B. Normal serum phosphate levels, C. Normal serum alkaline phosphatase level, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]