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 level are increased by - \nSelect and explain. \nA. ↓PO2, B. ↓PCO2, C. ↓Hb, D. ↓pH', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Hypoxia stimulates the release of Erythropoietin.', 'role': 'assistant'}]