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': 'BIS-GMA in composites \nSelect and explain. \nA. Replaced strontium filler particles, B. Replaced acid soluble glass particles, C. Replaced silane coupling agents, D. Replaced methacrylate based matrix', 'role': 'user'}, {'content': 'Answer: D \nExplanation: None', 'role': 'assistant'}]