This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Peripheral Nerve Injury, Subject name: Orthopaedics
A 10-year-old boy has severed his radial nerve. Which of the following cells plays a major role in axonal regrowth? 
Select and explain. 
A. Fibrous astrocytes, B. Fibroblasts, C. Oligodendrocytes, D. Schwann cells
D: Schwann cells
Answer: D: Schwann cells 
Explanation: Schwann cells play a major role in axon regeneration (axon regrowth) in the PNS