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': 'Type I gypsum product is also called \nSelect and explain. \nA. Impression plaster, B. Class I stone / Hydrocal, C. Class II stone/Densite, D. Model plaster', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]