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
Classification system of bone tumors is - 
Select and explain. 
A. Enneking, B. Manchester, C. Edmonton, D. TNM
A: Enneking
Answer: A: Enneking 
Explanation: According to Ennecking staging of benign tumors Stage 1-latent Stage2-active Stage3-inactive REF : MAHESWARI 9TH ED