This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Anesthesia, Subject name: Pharmacology
[{'content': 'Local anesthetics act by: \nSelect and explain. \nA. Affecting at the spinal level, B. Affecting the Na+ channels, C. Affecting the K+ channels, D. Blocking axonal transpo', 'role': 'user'}, {'content': 'Answer: B \nExplanation: The primary mechanism of action is by blockade of voltage gated sodium channels and block sodium entry into cell. From padmaja 4th edition Page no 200', 'role': 'assistant'}]