This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: JIPMER 2018, Subject name: Anaesthesia
[{'content': 'Local anesthetic acts by: \nSelect and explain. \nA. Blocking sodium gated channel, B. Blocking calcium gated channel, C. Blocking potassium gated channel, D. Blocking chloride gated channel', 'role': 'user'}, {'content': 'Answer: A \nExplanation: NORMAL LOCAL ANESTHETIC Sodium passess through voltage gated sodium channel and cause change in membrane potential and cause depolarization. Local anesthetic attatches to sodium channel and prevents propogation & depolarization. LA also has mild action on potassium calcium and NMDA channels', 'role': 'assistant'}]