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
Glass ionomer cement is composed of: 
Select and explain. 
A. 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
C: Aluminia silicate powder and poly carboxylic liquid
Answer: C: Aluminia silicate powder and poly carboxylic liquid 
Explanation: None