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: Medicine
[{'content': 'Commonest site of metastases is - \nSelect and explain. \nA. Lung, B. Brain, C. Liver, D. Kidney', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]