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: Pathology
[{'content': 'Cobblestone appearance of oral mucosa: \nSelect and explain. \nA. Crohn disease., B. Ulcerative colitis., C. Whipple disease., D. All of the above.', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Crohn disease:\n\nA type of granulomatous disease involving the intestinal mucosa\nAlso called regional enteritis\nCharacterized by granulomatous, superficial ulcerations of the intestinal tract with frequent fistulas developing onto body surfaces or viscera, or between intestinal loops.', 'role': 'assistant'}]