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
In expansion screws an expansion of 90° causes an expansion of: 
Select and explain. 
A. 0.20 mm, B. 0.10 mm, C. 0.36 mm, D. 0.09 mm
A: 0.20 mm
Answer: A: 0.20 mm 
Explanation: None