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
Fever persisting even after treatment of pneumonia. The likely diagnosis is 
Select and explain. 
A. Empyema, B. Fungal lesion, C. Hydrothorax, D. All of the above
A: Empyema
Answer: A: Empyema 
Explanation: None