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
Which of the following condition is considered as a premalignant condition for secondary osteosarcoma? 
Select and explain. 
A. Paget's disease, B. Enchondromatosis, C. Diaphyseal aclasis, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Pre-malignant bone lesions of secondary osteosarcoma : Paget's disease Diaphyseal aclasis Enchondromatosis Post-radiation Fibrous dysplasia Reference: Maheshwari; Essential Ohopaedics 9th ed; Page no: 242