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 metastatic tumour least common in - 
Select and explain. 
A. Pelvis, B. Ribs, C. Small bone of lower limb, D. Vertebra
C: Small bone of lower limb
Answer: C: Small bone of lower limb 
Explanation: The commonest sites for bone metastases are the vertebrae (commonest), pelvis, the proximal half of the femur, the humerus and ribs.
Extremities distal to elbow and knee are least commonly involved sites.