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': 'Cervical cross section of maxillary first premolar has: \nSelect and explain. \nA. A round shape, B. Elliptical shape, C. Oval shape, D. Square shape', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]