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': 'Size of periochip: \nSelect and explain. \nA. 4×5×0.35mm, B. 3×4×0.35mm, C. 3×4×0.35mm, D. 4×5×0.35 mm', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]