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
[{'content': "Most common site of Ewing's sarcoma ? \nSelect and explain. \nA. Upper end of tibia, B. Shaft of tibia, C. Lower end of femur, D. Shaft of femur", 'role': 'user'}, {'content': "Answer: D \nExplanation: Ans. is 'd' i.e., Shaft of femur Commonest site Ivory osteoma - Frontal sinus Osteoid osteoma - Tibia Admantinoma (Ameloblastoma) - Mandible Chordoma - Sacrum and cervical spine Osteoclastoma - Lower end of femur Ewing's sarcoma - Femur diaphysis > tibia diaphysis Osteosarcoma - Distal femur (45%), Proximal tibia (25%) Simple bone cyst - Proximal humerus Aneurysmal bone cyst - Bones around knee (Femur, tibia) Osteochondroma - Bones around knee (distal femur > proximal tibia) Fibrous dysplasia - Proximal femur > Tibia Enchondroma - Phalanges of hand Multiple myeloma - Veebrae Metastasis - Veebrae", 'role': 'assistant'}]