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: Anatomy
[{'content': 'A posteriorly perforating ulcer in the pyloric antrum of the stomach is likely to produce initial localized peritonitis or abscess formation in the - \nSelect and explain. \nA. Greater sac, B. Left subhepatic and hepatorenal spaces (pouch of Morrison), C. Omental bursa, D. Right subphrenic space', 'role': 'user'}, {'content': 'Answer: C \nExplanation: A posterior gastric ulcer may perforate into the lesser sac (omental bursa).\nThe leaking fluid passes out through epiploic foramen to reach the hepatorenal pouch.\nSometimes in these cases, the epiploic foramen is closed by adhesions.\nThen the lesser sac becomes distended and can be drained by a tube passed through the lesser omentum.', 'role': 'assistant'}]