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
The flutes of McSpadden Compactor are similar to: 
Select and explain. 
A. Lentulo Spiral fillers, B. Engine driven reamers, C. Flutes of Hedstorem in reverse, D. K-Flex file
C: Flutes of Hedstorem in reverse
Answer: C: Flutes of Hedstorem in reverse 
Explanation: None