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
The karat of gold foil used for restoration is: 
Select and explain. 
A. 22, B. 24, C. 16, D. 20
B: 24
Answer: B: 24 
Explanation: Gold foil is made up of 24 karat gold.
Ref : Physical properties of dental materials pg 34