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: Pediatrics
[{'content': "All of the following are true about Crohn's disease except. \nSelect and explain. \nA. Cobble stone appearance, B. Skip lesions seen, C. Perianal fistula is seen, D. It is superficial inflammation involving mucosa", 'role': 'user'}, {'content': "Answer: D \nExplanation: Crohn's disease is transmural inflammation involving all layers.", 'role': 'assistant'}]