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': 'Most common primary for metastatic colorectal cancer is ? \nSelect and explain. \nA. Squeamous cell carcinoma of lung, B. Hepatocellular  cancer, C. Adenocarcinoma of lung, D. Renal cell cancer', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Most comman primary for metastatic colorectal cancer is lives.', 'role': 'assistant'}]