This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Breast, Subject name: Pathology
All are Markers of bone formation except 
Select and explain. 
A. Osteocalcin, B. Alkaline phosphatase, C. Procollagen residue, D. Hydroxyproline
D: Hydroxyproline
Answer: D: Hydroxyproline 
Explanation: Osteocalcin,Alkaline phosphatase & Procollagen residue are Markers of bone formation. Refer robbins 9/e p774