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: Pharmacology
Which among the following is NOT used for surface anesthesia? 
Select and explain. 
A. Lignocaine, B. Procaine, C. Tetracaine, D. Benzocaine
B: Procaine
Answer: B: Procaine 
Explanation: None