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': "Most common cause of hypercapnic respiratory failure: March 2011,'Parch 2013 (a, b, h) \nSelect and explain. \nA. Acute asthma, B. Aspergillosis, C. COPD, D. Pneumothorax", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Ans. C: COPD Causes of type II (hypercapnic) respiratory failure: Chronic causes: COPD, sleep apnea, kyphscoliosis, myopathies/ muscular dystrophies, ankylosing spondylitis; Acute causes: Acute severe asthma (NOT acute asthma), acute exacerbation of COPD, upper airway obstruction, narcotic drugs etc. Type II respiratory failure: Reduced PaO2 Increased PaCO2 Normal P(A-a)O2 Hypoxemia with increased PaCO2 Type I respiratory failure: Reduced PaO2 Normal/ decreased PaCO2 INcreased P(A-a)O2 Hypoxemia with decreased PaCO2', 'role': 'assistant'}]