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
Acute exacerbation of COPD is done by all except: 
Select and explain. 
A. Pneumococcus, B. Moraxella catarrhalis, C. H. influenza, D. Staph. aureus
D: Staph. aureus
Answer: D: Staph. aureus 
Explanation: Bacterias like Pneumococcus , Moraxella catarrhalis are implicated in exacerbation of COPD.