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
All of the local anaesthetics given below are amides, EXCEPT: 
Select and explain. 
A. Lignocaine, B. Procaine, C. Prilocaine, D. Etidocaine
B: Procaine
Answer: B: Procaine 
Explanation: Clinical local anesthetics belong to one of two classes: aminoamide and aminoester local anesthetics. Procaine is an ester anaesthetic. The members of Amide group are: Aicaine Bupivacaine Cinchocaine/Dibucaine Etidocaine Levobupivacaine Lidocaine/Lignocaine Mepivacaine Prilocaine Ropivacaine Trimecaine