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': 'A 27 year old male patient complains of discoloration with his upper front teeth. Intra-oral examination reveals proximal caries with 11 and 21. Dentist prepares the tooth to receive composite restoration.\xa0Optimal enamel bevel features seen with this type of restoration is: \nSelect and explain. \nA. 45 degree bevel with 0.5-1.5mm width, B. 30 degree bevel with 0.5-1.5 mm width, C. 45 degree bevel with 2-3 mm width, D. 30 degree bevel with 2-3 mm width', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Enamel margins are beveled with a FLAME SHAPED OR ROUND DIAMOND INSTRUMENT .\nBevel is prepared by creating a 45 degree angle to the internal surface and width of 0.5-2mm depending on the size of the preparation, location of margin and esthetic requirement.', 'role': 'assistant'}]