This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory system, 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: Patients with COPD are frequently colonised with potential respiratory pathogens.Bacteria frequently implicated in COPD exacerbations include Streptococcus pneumoniae,Haemophilus influenzae, and Moraxella catarrhalis.In addition,Mycoplasma pneumoniae or Chlamydia pneumoniae are found in 5-10% of exacerbations. Harrison's medicine-18th edition,page no:2158.