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
Which of the following increases castability of base metal alloys? 
Select and explain. 
A. Tin, B. Beryllium, C. Molybdenum, D. Carbon
B: Beryllium
Answer: B: Beryllium 
Explanation: Beryllium refines grain size, which increases strength, and lowers the fusion temperature of the alloys, which improves castability. Manganese and silicon also improve the castability of the alloys.
Phillips 12 ed  page no 375