This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anatomy of Bone & Fracture Healing, Subject name: Orthopaedics
Regarding bone remodelling, all are true except: 
Select and explain. 
A. Osteoclastic activity at the compression site, B. Osteoclastic activity at the tension site, C. Osteoclastic activity and osteoblastic activity are both needed for bone remodelling in cortical and cancellous bones, D. Osteoblasts transforms into osteocytes
A: Osteoclastic activity at the compression site
Answer: A: Osteoclastic activity at the compression site 
Explanation: (a) Osteoclastic activity at the compression siteThus bone remodelling has both osteoclastic and osteoblastic activity at compression or tension side but the forces on bone decide where remodelling takes place compressile forces compression site and tensile forces tension site and in bone modelling there is osteoclastic activity at tension site and osteoblastic activity at compression site. Thus the best answer here will be (a) but this is with respect to modelling not remodelling.