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': 'Brazilian test is used to determine the ultimate tensile strength of \nSelect and explain. \nA. Ductile materials, B. Flexible materials, C. Brittle materials, D. Malleable materials', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]