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': 'True statement about pelvic abscess is \nSelect and explain. \nA. Uncommon cause of intra peritoneal abscess, B. Associated with pyothorax, C. May spontaneously drain via rectum, D. Identified by CT if there is full bladder', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Pelvic abscess :\n\nIt is common cause intraperitoneal abscess.\nIt is easily identified by CT if the bladder is empty.', 'role': 'assistant'}]