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
In facial porcelain margin, the risk of fracture can be reduced by 
Select and explain. 
A. Increased axial depth upto 3 mm, B. Cavosurface margin at 90 degree, C. Margins of the tooth reduction at incisal edge, D. Providing contact during centric relationship
B: Cavosurface margin at 90 degree
Answer: B: Cavosurface margin at 90 degree 
Explanation: None