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
Which one of the following local anaesthetics belongs to the ester group? 
Select and explain. 
A. Procaine, B. Buovacaine, C. Lignocaine, D. Mepivacaine
A: Procaine
Answer: A: Procaine 
Explanation: None