Which of the Following Statements About Osteosarcoma Is True

Which of the following statements about osteosarcoma is true?

A) It rarely occurs in African Americans.
B) The amount of tumor necrosis at resection is an important prognostic factor.
C) The addition of ifosfamide and etoposide to standard VACA-based chemotherapy improves survival for patients with nonmetastatic disease.
D) Radiation therapy is the preferred treatment for local control.