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
When selecting the colour of cement to use for cementing a porcelain jacket crown, the powder being tested is best mixed with: 
Select and explain. 
A. Glycerin-water solution, B. Cement liquid, C. Alcohol, D. Only water
A: Glycerin-water solution
Answer: A: Glycerin-water solution 
Explanation: Self-cured and dual-cured materials can be opaque or translucent, and those indicated for cementation of ceramic restorations are usually provided in several shades. Light-cured materials are indicated for bonding of laminated ceramic veneers (esthetic cements) or orthodontic brackets. Some esthetic resin cements used for cementation of veneers include glycerin-based, water-soluble “try-in” pastes to help with shade selection.
Reference: Craig’s 14th ed page no 289