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 important prognostic factor for colorectal carcinoma is \nSelect and explain. \nA. Site of lesion, B. Tumour size & characteristics, C. Age of patient, D. Lymph node status', 'role': 'user'}, {'content': 'Answer: D \nExplanation: "The number of positive nodes appeared to be the single most important prognostic factor."-DeVita', 'role': 'assistant'}]