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': 'Non-depolarizing blockade is potentiated by: \nSelect and explain. \nA. Hyperkalemia, B. Hypomagnesemia, C. Chronic Phenytoin therapy, D. Quininidine', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Neuromuscular-blocking drugs block neuromuscular transmission at the neuromuscular junction, causing paralysis of the affected skeletal muscles. This is accomplished either by acting presynaptically the inhibition of acetylcholine (ACh) synthesis or release or by acting postsynaptically at the acetylcholine receptors of the motor nerve end-plate. While some drugs act presynaptically (such as botulinum toxinand tetanus toxin), those of current clinical impoance work postsynaptically.', 'role': 'assistant'}]