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': 'Why a hard surface is necessary for a die stone: \nSelect and explain. \nA. To prevent breakage of die., B. To prevent water absorption., C. To make surface abrasion resistant., D. To easy removal of wax pattern.', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]