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: Unknown
[{'content': 'The local anesthetic with the longest duration of action is \nSelect and explain. \nA. Procaine, B. Chlorprocaine, C. Lignocaine, D. Dibucaine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Longest acting, most potent and most toxic local anesthetic is dibucaine.\nChlorprocaine is the shortest acting local anesthetic.', 'role': 'assistant'}]