This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Upper limb, Subject name: Anatomy
Rider's bones are ossification of 
Select and explain. 
A. Adductor brevis, B. Adductor longus, C. Adductor magnus, D. Flexor digitorum superficialis
B: Adductor longus
Answer: B: Adductor longus 
Explanation: Rider's bone develops in the tendon of adductor longus in professional riders. It is a sesamoid bone.that has no periosteum and ossifies after bih. Reference: BD Chaurasia's handbook of general anatomy, 5th edition, pg 55