This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lower limb, Subject name: Anatomy
Rider's bone ossify in the 
Select and explain. 
A. Adductor Longus, B. Gluteus Maximus, C. Lateral head of Gastronemius, D. Tibialis Posterior
A: Adductor Longus
Answer: A: Adductor Longus 
Explanation: In horse riders, the rounded tendon of adductor longus frequently gets calcified as a result of its friction together with the horseback. This calcified tendon is named rider's bone.Reference: Chaurasia Volume II; 7th edition; Page no: 41