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': 'Secondaries are common in a/e - \nSelect and explain. \nA. Skull, B. Hand & feet bones, C. Proximal limb bones, D. Pelvic', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Metastasis may occur in\xa0any bone but most commonly involve axial skeleton (e.g. vertebra, pelvis, ribs. skull, sternum) Proximal femur, and humerus in descending order.\nRed marrow in these areas are rich in capillary network, slow blood flow and nutrient environment facilitates the implantation and growth of the tumour cells.\nMetastasis in small bone of hand and feet are uncommon.\nMetastatic tumors are the most common form of skeletal malignancy.', 'role': 'assistant'}]