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': 'Slot size commonly used in orthodontics is: \nSelect and explain. \nA. 0.017 x 0.021, B. 0.014 x 0.024, C. 0.018 x 0.025, D. 0.010 x 0.020', 'role': 'user'}, {'content': 'Answer: C \nExplanation: The most commonly used slot size is 0.022*0.028 inch followed by 0.018*0.025 inch slot.', 'role': 'assistant'}]