This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen & Pelvis, Subject name: Anatomy
Peyer's patches are present in: 
Select and explain. 
A. Duodenum, B. Jejunum, C. Ileum, D. Colon
C: Ileum
Answer: C: Ileum 
Explanation: Ans. C. IleumPeyer's patches are small masses of lymphatic tissue found throughout the ileum region of the small intestine. Also known as aggregated lymphoid nodules, they form an important part of the immune system by monitoring intestinal bacteria populations and preventing the growth of pathogenic bacteria in the intestines.