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
Arrange the following long acting LA in descending order of their duration of action. 
Select and explain. 
A. Dibucaine>Etidocaine>Tetracaine> Bupivacaine., B. Dibucaine>Tetracaine>Bupivacaine> Etidocaine., C. Tetracaine>Dibucaine>Bupivacaine>Etidocaine., D. Tetracaine>Bupivacaine>Dibucaine> Etidocaine.
A: Dibucaine>Etidocaine>Tetracaine> Bupivacaine.
Answer: A: Dibucaine>Etidocaine>Tetracaine> Bupivacaine. 
Explanation: Dibucaine is longest acting and most toxic.
Etidocaine: 200minutes.
Tetracaine~Bupivacaine:175 minutes.