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': 'Which of the following type of GIC is used as a base? \nSelect and explain. \nA. Type I, B. Type IIa, C. Type IIb, D. Type III', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Type I: Luting crowns, bridges\xa0and orthodontic brackets.\nType IIa: Esthetic restorative cements.\nType IIb: Reinforced restorative cements.\nType III: Lining cements, base.\nRef: Phillip’s Science of Dental Materials ed 12 pg 320', 'role': 'assistant'}]