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': 'Glass ionomer cement is composed of: \nSelect and explain. \nA. Zinc oxide powder and poly carboxylic liquid, B. Zinc oxide powder and phosphoric acid, C. Aluminia silicate powder and poly carboxylic liquid, D. Aluminia silicate powder and phosphoric acid', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]