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
Which enzyme participates in the deposition of hydroxyapatite crystals in bone: 
Select and explain. 
A. Alkaline phosphate, B. Adenosine triphosphate., C. Pyrophosphate., D. All of the above.
D: All of the above.
Answer: D: All of the above. 
Explanation: None