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: Pathology
[{'content': 'The commonest site of lytic lesion in multiple myeloma is - \nSelect and explain. \nA. Vertebral column, B. Femur, C. Clavicle, D. Pelvis', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]