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: Physiology
[{'content': 'Most impoant stimulus to peripheral chemoreceptors \nSelect and explain. \nA. PO2, B. CO2, C. pH, D. HCO3', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Peripheral chemoreceptors are activated by changes in the paial pressure of oxygen and trigger respiratory drive changes aimed at maintaining normal paial pressure levels.Ref: Ganong review of medical physiology 23rd edition Page no: 562', 'role': 'assistant'}]