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
Most common primary bone tumour in adult bone is: 
Select and explain. 
A. Chondro sarcoma, B. Osteogenic sarcoma, C. Admintinoma, D. Ewing's sarcoma
B: Osteogenic sarcoma
Answer: B: Osteogenic sarcoma 
Explanation: (osteogenic sarcoma) (218-M) (185-Appley's 8th)* Osteogenic sarcoma is highly malignant primary bone tumour - (Common in Age 15-25 years)* Osteoid osteoma - is the commonest true benign tumour of the bone.