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: Pharmacology
Which of the following local anesthetic should be avoided in spinal anesthesia? 
Select and explain. 
A. Mepivacaine, B. Prilocaine, C. Bupivacaine, D. Chlorprocaine
D: Chlorprocaine
Answer: D: Chlorprocaine 
Explanation: Chlorprocaine is avoided in spinal anesthesia as it can cause spinal paraplegia because of a neurotoxic compound sodium metabisulphite, which is used as a preservative.