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
Continuous diaphragm sign is seen in 
Select and explain. 
A. Pneumo mediastinium, B. Pseudo pneumomediastrinium, C. Pleural effusion, D. Pulmonary infarct
A: Pneumo mediastinium
Answer: A: Pneumo mediastinium 
Explanation: Air collects beneath the pericardium so the central part of diaphragm become visible represents pneumo mediastinium.