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': 'Which of the following is not an ester – \nSelect and explain. \nA. Amethocaine, B. Benzocaine, C. Procaine, D. Bupivacaine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Bupivacaine is an amide.', 'role': 'assistant'}]