This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gastrointestinal Radiology, Subject name: Radiology
Air under central tendon of diaphragm is 
Select and explain. 
A. Air under diaphragm sign, B. Cupola sign, C. Doges cap sign, D. Falciform ligament sign
B: Cupola sign
Answer: B: Cupola sign 
Explanation: The 'Cupola sign' is seen on a supine chest/abdominal radiograph in the presence of pneumoperitoneum. It refers to non-dependent gas that rises within the abdominal cavity of the supine patient to accumulate underneath the central tendon of the diaphragm in the midline.