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
Surface on which crack 1st appear in connector made up of ceramic: 
Select and explain. 
A. Occlusal surface, B. Gingival surface., C. Proximal surface., D. Buccal surface.
B: Gingival surface.
Answer: B: Gingival surface. 
Explanation: None