This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Other topics and Adverse effects, Subject name: Pharmacology
[{'content': 'Which of the following drugs has a high surface activity and vasoconstrictor actions that reduce bleeding in mucus membranes? \nSelect and explain. \nA. Bupivacaine, B. Cocaine, C. Lidocaine, D. Procaine', 'role': 'user'}, {'content': 'Answer: B \nExplanation: (Ref: KDT 6/e p356, 357) All LAs are vasodilators except cocaine. It possesses vasoconstrictor activity. Cocaine also has good surface activity.', 'role': 'assistant'}]