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: Surgery
The tensile strength of a bone is due to - 
Select and explain. 
A. Strands of collagen, B. Hydroxyapatite crystals, C. Periosteum, D. Metaphysis
A: Strands of collagen
Answer: A: Strands of collagen 
Explanation: Answer- A. Strands of collagenThe strands of collagen give bone its tensile strength, and the interspersed crystals of hydroryapatite give bone its compressional strength. These effects are synergistic.