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: Surgery
[{'content': 'Which one of the following local anaesthetics belongs to the ester group? \nSelect and explain. \nA. Procaine, B. Buovacaine, C. Lignocaine, D. Mepivacaine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]