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
Slot size commonly used in orthodontics is: 
Select and explain. 
A. 0.017 x 0.021, B. 0.014 x 0.024, C. 0.018 x 0.025, D. 0.010 x 0.020
C: 0.018 x 0.025
Answer: C: 0.018 x 0.025 
Explanation: The most commonly used slot size is 0.022*0.028 inch followed by 0.018*0.025 inch slot.