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
Which of the following types of nerve fibers carry pain? 
Select and explain. 
A. A a, B. A b, C. A g, D. A d
D: A d
Answer: D: A d 
Explanation: Delta fibres carry pain, cold, touch sensations. Ref: Ganong&;s review of medical physiology; 23rd edition; pg: 89; table 4-1