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': 'According to the Enneking system, not true regarding an active benign tumour is - \nSelect and explain. \nA. Intracapsular, B. Margin of reactive bone, C. Thick rim of reactive bone, D. Extended curettage is treatment', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Enneking active stage of benign tumors is stage 2 in which tumor is actively growing and can cause symptoms of pathological fracture.\nRadiograph shows well defined margins with a thin rim of reactive bone. Tumor may expand and thin the cortex.\nTreatment usually consists of extended curettage, e.g. in ABC.', 'role': 'assistant'}]