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
All of the following are indirect radiologic signs of the collapse of lung EXCEPT – 
Select and explain. 
A. Mediastinal displacement, B. Hilar displacement, C. Compensatory hyperinflation, D. Loss of aeration
D: Loss of aeration
Answer: D: Loss of aeration 
Explanation: Loss of aeration is a direct sign of lung collapse.
Other three options are indirect signs of lung collapse.