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
Cavosurface angle for amalgam is: 
Select and explain. 
A. >90°, B. < 90°, C. 90°, D. 0°
C: 90°
Answer: C: 90° 
Explanation: The design of the cavosurface angle depends on the restorative material being used. Because of the low edge strength of amalgam and glass-ceramic, a 90-degree cavosurface angle produces maximal strength for these materials.
Sturdevants operative dentistry 7th edition page 132.