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: Surgery
[{'content': 'The bone matrix has the following crystals ? \nSelect and explain. \nA. Calcium hydroxyapatite, B. Calcium pyrophosphate, C. Calcium phosphate, D. Calcium sulphate', 'role': 'user'}, {'content': "Answer: A \nExplanation: Ans. is 'a' i.e., Calcium hydroxyapatite Structure of bone Bone is a specialized connective tissue. o Bone components are :? Inorganic elements (65%) Organic matrix (35%) 1. Inorganic elements It is the mineral phase, principally composed of calcium and phosphate, mostly in the form of hydroxyapatite.", 'role': 'assistant'}]