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
Typically rapid palatal expansion is done with a jack screw that is activated at the rate of: 
Select and explain. 
A. 1.0 to 2.0 mm/week, B. 1.0 to 2.0 mm/day, C. 0.5 to 1.0 mm/week, D. 0.5 to 1.0 mm/day
D: 0.5 to 1.0 mm/day
Answer: D: 0.5 to 1.0 mm/day 
Explanation: Every turn of the screw opens the appliance by 0.25 mm. 
Each turn involves 90° activation. 
With rapid maxillary expansion at a rate of 0.5–1 mm/day, a 10 mm expansion is achieved in 2–3 weeks.

Textbook of ORTHODONTICS Sridhar Premkumar