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
[{'content': 'The flutes of McSpadden Compactor are similar to: \nSelect and explain. \nA. Lentulo Spiral fillers, B. Engine driven reamers, C. Flutes of Hedstorem in reverse, D. K-Flex file', 'role': 'user'}, {'content': 'Answer: C \nExplanation: None', 'role': 'assistant'}]