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
[{'content': 'Surface on which crack 1st appear in connector made up of ceramic: \nSelect and explain. \nA. Occlusal surface, B. Gingival surface., C. Proximal surface., D. Buccal surface.', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]