You are answering a USMLE-style medical question. Question: A 49-year-old man comes to the physician because of a 1-week history of diarrhea and abdominal bloating. His stools are bulky, foul-smelling, and difficult to flush. Over the past 6 months, he has had recurrent dull epigastric pain that is triggered by meals and lasts for a few days. He drinks 6 to 8 beers daily. Abdominal examination shows mild epigastric tenderness with no rebound or guarding. A CT scan of the abdomen is shown. The structure indicated by the arrows is most likely lined by which of the following? Options: A) Simple ductal epithelium B) Granulation tissue C) Pyogenic membrane D) Columnar mucinous epithelium Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.