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': 'Lower first molar has which of the following occlusal shapes \nSelect and explain. \nA. Pentagonal, B. Trapezoid, C. Rectangular, D. Any of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: In previous question only one has to be selected so answer should be Pentagonal. But other occlusal forms are also found in lower first molar.', 'role': 'assistant'}]