This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Tumors, Subject name: Orthopaedics
[{'content': 'According to Enneking system, not true regarding an active benign tumor 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: According to Ennecking staging of benign tumors Stage 2 active : Progressive growth limited by natural barriers Well defined margins but may expand thinning coex Negligible reccurence after marginal recurrence Treatment -marginal resection REF : MAHESWARI 9TH ED', 'role': 'assistant'}]