This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, Subject name: Medicine
[{'content': '. Respiratory centre depression is caused by all except- \nSelect and explain. \nA. Opium, B. Strychnine, C. Barbiturates, D. Gelsemium', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Strychnine is a toxic alkaloid that acts as an antagonist of the inhibitory glycine receptor of CNS,thereby producing overstimulation of nervous system. Barbiturates,opioids and gelsemium(yellow jasmine) are potential respiratory centre depressants.', 'role': 'assistant'}]