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': 'Porosity measurements in four types of hand-mixed  cements  showed  that __________  cement had the highest porosity. \nSelect and explain. \nA. Resin cement, B. GIC, C. Zinc phosphate cement, D. Polycarboxylate cement', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Porosity measurements in four types of hand-mixed\xa0cements\xa0showed\xa0that\xa0polycarboxylate\xa0cement had the highest porosity and resin cement had\xa0the\xa0least.\xa0Zinc\xa0phosphate\xa0and\xa0GICs\xa0had\xa0intermediate amounts of porosity.\nRef: Phillip’s Science of Dental Materials ed 12 pg 320', 'role': 'assistant'}]