This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Large intestine, Subject name: Surgery
[{'content': 'What is the investigation of choice for the diagnosis of colon cancer? \nSelect and explain. \nA. Barium enema, B. Colonoscopy + biopsy, C. USG, D. CT scan', 'role': 'user'}, {'content': 'Answer: B \nExplanation: IOC for diagnosis of colon cancer- Colonoscopy + biopsy IOC for staging of colon cancer- CECT Most impoant prognostic factor- stage (TNM) Single independent most impoant prognostic factor- LN status', 'role': 'assistant'}]