Indicators of bone formation include all of the following except -: (A) Osteocalcin, (B) Alkaline phosphatase, (C) Hydroxyproline, (D) Type 1 procollegen
Answer is C. Markers of bone formation 

Bone-specific alkaline phosphatase
Osteocalcin
Serum peptide of type I procollagen / Type I collagen extension peptide