This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pancreas, Subject name: Surgery
Rigler's sign is suggestive of - 
Select and explain. 
A. Pneumothorax, B. Pneumoperitoneum, C. Peritonitis, D. Hemothorax
B: Pneumoperitoneum
Answer: B: Pneumoperitoneum 
Explanation: Ans. is 'b' i.e., Pneumoperitoneum Rigler's Signo Both sides of bowel become visible because of free gas on an abdominal xray. This is known as Rigler's Sign.