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 margin angulation in chamfer finish line is: 
Select and explain. 
A. Always 90°, B. 90° or less than 90°, C. 90° or more than 90°, D. 120°
C: 90° or more than 90°
Answer: C: 90° or more than 90° 
Explanation: None