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': 'The most common site of hypersensitivity is \nSelect and explain. \nA. Cervical, B. Facial, C. Lingual, D. Occlusal', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Cervical hypersensitivity may be caused not only by chemical erosion, but also by mechanical abrasion or even occlusal stresses.', 'role': 'assistant'}]