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
[{'content': 'Which among the following is NOT used for surface anesthesia? \nSelect and explain. \nA. Lignocaine, B. Procaine, C. Tetracaine, D. Benzocaine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]