This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anaesthesia
[{'content': 'In spinal anesthesia which fiber is lost first \nSelect and explain. \nA. Sympathetic, B. Sensory, C. Motor, D. All', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Sympathetic', 'role': 'assistant'}]