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: Orthopaedics
[{'content': "All are true about Ewing's sarcoma except \nSelect and explain. \nA. Low grade tumor has good prognosis, B. Pain is most common symptom, C. Onion peel appearance, D. Associated with t(11,22)", 'role': 'user'}, {'content': "Answer: A \nExplanation: All cases of Ewing's sarcoma are considered as high grade.\nHistological grading has no prognostic significance.", 'role': 'assistant'}]