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 preferred for cutting ductile materials such as dentin? \nSelect and explain. \nA. Diamond burs, B. Carbide burs, C. Hand instruments, D. All of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Burs are generally preferred for cutting ductile materials such as dentin, whereas Diamonds are most efficient when used to cut brittle materials and are superior to burs for the removal of dental enamel.\nDental stones, especially diamonds, have the highest efficiency in removing enamel (brittle material), whereas carbide burs have the highest efficiency in removing dentin (elastic material). Removal of tooth structure using and stone should be confined to enamel and perhaps the superficial 0.5-1 mm.\n\nRef: Sturdevant's art and science of operative dentistry. 4th edition page 341\nOperative dentistry modern theory and practice Marzouk page 77", 'role': 'assistant'}]