This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdomen and pelvis, Subject name: Anatomy
Most common site of Mucosa-associated lymphoid tissue 
Select and explain. 
A. Duodenum, B. Jejunum, C. Ileum, D. Stomach
C: Ileum
Answer: C: Ileum 
Explanation: MALT lymphoma is a form of lymphoma involving the mucosa-associated lymphoid tissue (MALT), frequently of the stomach, but viually any mucosal site can be afflicted. It is cancer originating from B cells in the marginal zone of the MALT and is also called extranodal marginal zone B cell lymphoma. ref - pubmed.com