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': 'Most Pit and ﬁssure sealants are based on \nSelect and explain. \nA. Bis GMA, B. TEGDMA, C. UDMA, D. All of the above', 'role': 'user'}, {'content': 'Answer: A \nExplanation: The most common sealants are based on bisphenol A-glycidyl methacrylate (Bis-GMA) resin and are light-cured, although some self-cured products are also available. The viscous Bis-GMA resin is mixed with a diluent, such as triethylene glycol dimethacrylate, to produce a reasonably low-viscosity, ﬂowable resin.\nCraig Ed 14th P:123', 'role': 'assistant'}]