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 cavosurface margin for direct filling gold are prepared with 
Select and explain. 
A. 90° butt joint, B. 45° Bevelled, C. 30-40° bevel, D. 10° bevel
C: 30-40° bevel
Answer: C: 30-40° bevel 
Explanation: None