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: Surgery
[{'content': 'Most common site of metastasis of Medullary carcinoma of thyroid: \nSelect and explain. \nA. Liver, B. Lung, C. Kidney, D. Brain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Sites of spread of medullary thyroid carcinoma include local lymph nodes in the neck, lymph nodes in the central portion of the chest (mediastinum), liver, lung, and bone.\n\xa0Spread to other sites such as skin or brain occurs but is uncommon.\n\xa0Most common site of metastasis of Medullary carcinoma of thyroid is liver.', 'role': 'assistant'}]