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
Electrical conductivity speed of A α fibres ? 
Select and explain. 
A. 70-120, B. 50-70, C. 30-51, D. 20-Oct
A: 70-120
Answer: A: 70-120 
Explanation: None