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
Person wakes up with pain, paresthesia, tingling of the arms. He had slept with arm below the head. Which fibres are involved? 
Select and explain. 
A. Type A fibres, B. Type B, C. Type C (pain), D. Type C (postganglionic)
A: Type A fibres
Answer: A: Type A fibres 
Explanation: Pressure on a nerve cause loss of conduction in large diameter motor, touch and pressure ie type A fibre while pain fibre c remains intact. Ref: Ganong&;s review of medical physiology; 23rd edition; pg:89.