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': 'Local anaesthetics act by inhibiting - \nSelect and explain. \nA. Influx of K+, B. Efflux of K+, C. Influx of Na+, D. Efflux of Na+', 'role': 'user'}, {'content': "Answer: C \nExplanation: Ans. is 'c' i.e., Influx of Na+ The LAs block nerve conduction by decreasing the entry (influx) of Na+ ions during upstroke of action potential.", 'role': 'assistant'}]