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: Radiology
What is seen in the X-ray of femur below 
Select and explain. 
A. Sunburst calcification, B. Onion peel effect, C. Codmann triangle, D. Bone marrow invasion
C: Codmann triangle
Answer: C: Codmann triangle 
Explanation: .