This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Obstructive Pulmonary Disease, Subject name: Medicine
[{'content': 'Which of the folio wing is the least com mon bacteria responsible for Acute Exacerbation of Chronic Bronchitis - \nSelect and explain. \nA. Streptococcus pneumoniae, B. Moraxella catarrhalis, C. Haemophilus influenza, D. Staphylocccus aureus', 'role': 'user'}, {'content': "Answer: D \nExplanation: .Ans. is 'd' i.e., Staphylocccus aureus Most common bacterias associated with acute excerbation in COPDo Hemophilus influenzao Moraxella catarrhaliso Streptococcus pneumoniae", 'role': 'assistant'}]