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': 'Average bond strength in enamel adhesion: \nSelect and explain. \nA. 5-10 MPa, B. 20-50 MPa, C. 50-70 MPa, D. 70-100 MPa', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Bond strength of enamel is higher than bond strength to dentin.\nEnamel is 20-50 MPa.\nDentin is 15-25 MPa\xa0depending on agent used.\xa0\nReference-Sturdevant 6th ed\xa0 Pg: 116', 'role': 'assistant'}]