This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anaesthesia, Subject name: Pharmacology
The local anaesthetic with the longest duration of action is : 
Select and explain. 
A. Procaine, B. Chlorprocaine, C. Lignocaine, D. Dibucaine
D: Dibucaine
Answer: D: Dibucaine 
Explanation: * Longest acting, most potent and most toxic LA is dibucaine. * Chlorprocaine is the shoest acting LA.