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 is an important marker for bone remodelling: 
Select and explain. 
A. Serum alkaline phosphate., B. Calcium., C. Hydroxyproline., D. Beta2 microglobulin
D: Beta2 microglobulin
Answer: D: Beta2 microglobulin 
Explanation: The important markers for bone turnover include serum alkaline phosphates for bone formation, urinary calcium and hydroxyproline for bone resorption, and serum β2 microglobulin for bone remodeling.