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': 'Plica circularis is absent in: \nSelect and explain. \nA. Duodenum, B. Jejunum, C. Proximal ileum, D. Distal ileum', 'role': 'user'}, {'content': "Answer: D \nExplanation: Luminal surface of small bowel reveals mucosal folds called plicae circulares Numerous in the proximal jejunumIt decreases in distal small bowelAbsent in terminal ileum Aggregates of lymphoid follicles are highest in the ileum (Peyer's patches)Peyer's patches are more prominent during infancy and childhood. Ref: Sleisenger, E - 9, P-1615", 'role': 'assistant'}]