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': 'Dull appearance of mouth temperature wax indicates \nSelect and explain. \nA. Insufficient material, B. Overextension, C. Contact of the material with tissues, D. Partial contact of tissues', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]