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
If the nib diameter is reduced by half, the compaction force is 
Select and explain. 
A. Halved, B. double, C. Increases 4 times, D. constant
C: Increases 4 times
Answer: C: Increases 4 times 
Explanation: None