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 size of sprue in casting an average bicuspid M.O.D. casting by centrifugal force is 
Select and explain. 
A. 10 gauge, B. 12 gauge, C. 16 gauge, D. 20 gauge
B: 12 gauge
Answer: B: 12 gauge 
Explanation: None