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': 'Prognosis for carcinoma rectum is best assessed by - \nSelect and explain. \nA. Site of tumour, B. Histological grading, C. Size of tumours, D. Duration of the symptoms', 'role': 'user'}, {'content': 'Answer: B \nExplanation: No effect on Prognosis: Tumor size and duration of symptoms.\nTumor size and configuration (endophytic, exophytic, annular) do not carry any prognostic significance\xa0in colorectal carcinoma.', 'role': 'assistant'}]