This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Bone Tumour, Subject name: Orthopaedics
Commonest site of the simple bone cyst is 
Select and explain. 
A. Upper end of femur, B. Lower end of femur, C. Upper end of humerus, D. Lower end of humerus
C: Upper end of humerus
Answer: C: Upper end of humerus 
Explanation: (Upper end of humerus) (180- Abley's 8th)* Simple bone cyst - commonest being the upper end of the humerus* Spine is commonest site of the osseous haemangioma* Commonest site of Giant cell tumour - Distal femur, proximal tibia, proximal humerus and distal radius* Commonest site of osteogenic sarcoma - Lower end of the femur, upper end of the tibia and upper end of the humerus* Commonest site of Ewing's sarcoma - usually in a tubular bone and especially in the Tibia, Fibula or clavicle* Ewing *s tumour is the commonest malignant tumour of flat bone, which has multi-centric origin* Aneurysmal bone cyst - Tibia, Humerus