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
Blood gas measurements of a patient shows the followilng values pH 7.2, p CO2 80 mmHg,pO2 46 mmHg. Which of the following could be the most probable diagnosis - 
Select and explain. 
A. Acute asthma, B. Acute exacerbation of COPD, C. ARDS, D. Severe pneumonia
B: Acute exacerbation of COPD
Answer: B: Acute exacerbation of COPD 
Explanation: None