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': 'Vimal, a 70 years old male presents with a h/o lower GI bleed for last 6 months. Sigmoidoscopic examination shows a mass, of 4 cms about 3.5 cms above the anal verge. The treatment of choice is - \nSelect and explain. \nA. Colostomy, B. Anterior resection, C. Abdominoperineal resection, D. Defunctioning anastomosis', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]