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: Physiology
[{'content': 'Erythropoietin secretion occurs when: \nSelect and explain. \nA. Tissue pO2 concentration, B. T Tissue pH, C. T Tissue pCO2 concentration, D. T Hemoglobin', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. 4, Tissue PO2 concentrationThe only physiological stimulus for erythropoietin secretion is Hypoxia or decreased paial pressure of oxygenQ.', 'role': 'assistant'}]