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': 'Maximum stress that a material can withstand without permanent deformation is known as: \nSelect and explain. \nA. Proportional limit., B. Elastic limit., C. Strain., D. Yield strength.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]