This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pneumonia, Bronchiectasis, and Lung Abscess, Subject name: Medicine
Most common cause of empyema is: 
Select and explain. 
A. Bronchopleural fistula, B. Tubercular pneumonia, C. Bacterial pneumonia, D. Pleurisy
C: Bacterial pneumonia
Answer: C: Bacterial pneumonia 
Explanation: Ans. is 'c' Bacterial pneumonia .Causes of empyema in decreasing order of frequency.Bacterial pneumoniaT.B. pneumoniaBronchiectasisLung abscess