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': "The sac contains only a portion of the circumference of the intestine \nSelect and explain. \nA. Richter's hernia, B. Littre's hernia, C. Spigelian hernia, D. Lumber hernia", 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]