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
Group B fibers are: 
Select and explain. 
A. Sympathetic preganglionic, B. Sympathetic postganglionic, C. Parasympathetic postganglionic, D. All
A: Sympathetic preganglionic
Answer: A: Sympathetic preganglionic 
Explanation: Group B fibers are preganglionic fibers .. They are myelinated Ref:Guyton and Hall textbook of medical physiology 12th edition,page number: 73