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: Anatomy
All are predisposing factors of Osteogenic sarcoma except 
Select and explain. 
A. Pagets disease of bone, B. Radiation, C. Viral infection, D. Bone infection
C: Viral infection
Answer: C: Viral infection 
Explanation: Causes of secondary Osteosarcoma Paget disease. Radiation Fibrous dysplasia Enchondromatosis Multiple osteochindroma Bone infraction Chronic osteomyelitis Refer Maheshwari 9th/e p 239