<prompt> Secondary osteosarcoma are associated with -Pagets diseaseOsteogenesis imperfectaMelhoreostosisAnkylosing spondylitis  <response>: Ans. is a i.e., Pagets disease Causes of secondary osteosarcomao Pagets Diseaseo Fibrous dysplasiao Radiationo Enchondromatosiso Hereditary multiple exostosiso Chronic osteomyelitiso Bone infarction 