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: Medicine
[{'content': 'Which of the following is used for improving long term prognosis in COPD with resting hypoxemia:March 2011 \nSelect and explain. \nA. Oxygen, B. Beta-2 agonist, C. Inhaled steroids, D. Systemic steroids', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. A : OxygenLong term home oxygen therapy improves survival in selected patients with COPD complicated by severe hypoxemia (aerial Pa02 less than 8.0 kPa/ 55 mmHg)', 'role': 'assistant'}]