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
[{'content': 'Which of the following local anaesthetics are not vasodilators \nSelect and explain. \nA. Lignocaine, B. Bupivacaine, C. Benzocaine, D. Tetracaine', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Lignocaine has no vasogenic action.', 'role': 'assistant'}]