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
In type II gold alloys,  __________  Karat gold is used. 
Select and explain. 
A. 20 K, B. 24 K, C. 18 K, D. 10 K
A: 20 K
Answer: A: 20 K 
Explanation: Types of dental casting gold alloys 
Dental casting gold alloys 

High carat gold alloy (gold alloys by type) (gold-silver-copper alloys) 
	Type 1 - 22K gold alloy
	Type 2 - 20K gold alloy
	Type 3 - 18K gold alloy
	Type 4 - Gold platinum alloy
	               14K gold alloy 
Medium carat gold alloy
Low carat gold alloy 

Advances in metallic biomaterials processing & applications pg 262