This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolic Disorders Leading to Osteosclerosis, Subject name: Orthopaedics
Secondary osteosarcoma are associated with - 
Select and explain. 
A. Paget's disease, B. Osteogenesis imperfecta, C. Melhoreostosis, D. Ankylosing spondylitis
A: Paget's disease
Answer: A: Paget's disease 
Explanation: Ans. is 'a' i.e., Paget's disease Causes of secondary osteosarcomao Pagets Diseaseo Fibrous dysplasiao Radiationo Enchondromatosiso Hereditary multiple exostosiso Chronic osteomyelitiso Bone infarction