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': 'Which one of the following provides most conservative approach while restoring the tooth? \nSelect and explain. \nA. Cast gold, B. Dental amalgam, C. Glass ionomer cement, D. Composite resin', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]