You are answering a USMLE-style medical question. Question: A 34-year-old man comes to the physician because of a 3-week history of colicky abdominal pain and diarrhea. He has bowel movements 10–12 times daily; the stool contains blood and mucus. He constantly has the urge to defecate. His vital signs are within normal limits. Examination of the abdomen shows diffuse tenderness to palpation. Serum concentration of C-reactive protein is 20 mg/L (N<10). Colonoscopy shows a bleeding, ulcerated rectal mucosa with several pseudopolyps. Which of the following is this patient at greatest risk of developing? Options: A) Hemolytic uremic syndrome B) Oral ulcers C) Colorectal cancer D) Pancreatic cancer Reply with ONLY the letter of the correct answer (A, B, C, or D). No explanation.