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': 'Upper 2nd premolar’s occlusal view \nSelect and explain. \nA. Ovoid > Hexagonal, B. Hexagonal > Ovoid, C. Ovoid always, D. Hexagonal always', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]