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 is the most preferred luting agent used for cementing pins in vital teeth? \nSelect and explain. \nA. Zinc phosphate, B. Zinc phosphate with cavity liner, C. Poly carboxylate, D. Glass Ionomer', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]