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': 'Transverse section of Class V through the axial wall is \nSelect and explain. \nA. Convex, B. Concave, C. Kidney shaped, D. Straight', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]