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 of the following is an example of a composite\nmaterial? \nSelect and explain. \nA. A filled resin, B. Colloidal silica, C. Gold alloy, D. Wax', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]