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: Radiology
Increased radiolucency of one sided hemithorax may he caused by all the following except: 
Select and explain. 
A. Obstructive emphysema, B. Pneumothorax, C. Expiratory film, D. Rotation
C: Expiratory film
Answer: C: Expiratory film 
Explanation: Ans. Expiratory film