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
Which of the following constituents is common in occlusal sealants, bonding agents, composite resins? 
Select and explain. 
A. BIS GMA, B. Polymethyl methacrylate, C. Benzoin methyl ether, D. Silica filter
A: BIS GMA
Answer: A: BIS GMA 
Explanation: None