This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: All India exam, Subject name: Pathology
A 25-year-old male presents with swelling over right knee since 1 month. The radiograph is shown here. Which of the following statement is true regarding this condition? 
Select and explain. 
A. It is a bone forming primary malignant tumour of bone, B. Codmans triangle can be seen, C. Hematogenous spread with lung metastasis are common., D. All of above
D: All of above
Answer: D: All of above 
Explanation: Osteosarcoma This primary malignant bone-forming neoplasm is rare, but is still the commonest primary malignant lesion of bone after myeloma.