This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Orthopaedics
A 45 yrs male presented with an expansile lesion in the centre of femoral metaphysis. The lesion shows endosteal scalloping & punctuate calcifications.Most likely diagnosis is - 
Select and explain. 
A. Osteosarcoma, B. Chondrosarcoma, C. Simple bone cyst, D. Fibrous Dysplasia
B: Chondrosarcoma
Answer: B: Chondrosarcoma 
Explanation: You can simply solve this question by knowing very simple fact that punctate calcification is seen in cartilaginous tumors and amongst the given options, only chondrosarcoma is cartilaginous.