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': 'A patient with a non obstructing carcinoma of the sigmoid colon is being prepared for elective resection. To minimize the risk of postoperative infectious complications, your planning should include \nSelect and explain. \nA. A single preoperative parenteral dose of antibiotic effective against aerobes and anaerobes., B. Avoidance of oral antibiotics to prevent emergence of clostridium difficile, C. Postoperative administration for 2 to 4 days of parenteral antibiotics effective against aerobes and anaerobes, D. Postoperative administration for 5 to 7 days of parenteral antibiotics effective against aerobes and anaerobes', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Many clinical and experimental studies have looked at the optimum bowel preparation and preoperative regimen for elective colonic surgery to reduce the postoperative infectious complications of wound infection, intra-abdominal abscess, and anastomotic leakage. Currently a postoperative rate of wound infection of only 5% can be attained by combining mechanical cleansing, oral antibiotics, and perioperative parenteral antibiotics. Oral antibiotics may be administered one hour prior to surgery and should cover all anaerobes (e.g., neomycin-erythromycin), antibiotics effective against aerobes (e.g., cefoxitin) should be administered in the operating room as a single dose and not postoperatively. Both antibiotic regimens are for prophylaxis without fostering resistant against microbes.', 'role': 'assistant'}]