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: Dental
[{'content': 'The schematic diagram shows appropriate pulp tissue zones following formocresol therapy, except \nSelect and explain. \nA. Stainless steel crown, B. ZOE buildup, C. Fixation zone, D. Vital Tissue', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]