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': 'How much reduction in strength and toughness in endodontically treated molars attributed to changes in collagen cross-linking and dehydration of dentin? \nSelect and explain. \nA. 5%, B. 14%, C. 21%, D. 60%', 'role': 'user'}, {'content': 'Answer: B \nExplanation: "Almost 14% reduction in toughness in endodontically molars compared with vital dentin due to changes in collagen cross- linking and dehydration of dentin".', 'role': 'assistant'}]