This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Regional anaesthesia, Subject name: Anaesthesia
[{'content': 'Local Anesthetic first used \nSelect and explain. \nA. Procaine, B. Lignocaine, C. Bupivacaine, D. Cocaine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Cocaine was the earliest used local anaesthesia(1st time used by Carl Koller in 1884 for occular surgery) cocaine is a naturaly occuring ester linked local anesthetic', 'role': 'assistant'}]