This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
A gamma nerve diameter is 
Select and explain. 
A. 13-20, B. 13-Apr, C. 6-Mar, D. 0.2-1.0
C: 6-Mar
Answer: C: 6-Mar 
Explanation: A delta fibre diameter is 3-6 um. Ref: Ganong&;s review of medical physiology; 23rd edition; pg: 89; table 4-1.