This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Abdominal Radiography, Subject name: Radiology
[{'content': 'Mercedes Benz sign is seen in: \nSelect and explain. \nA. Gall stone, B. Bladder stone, C. Renal stones, D. Foreign body bronchus', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) Gall stoneREF: Suttons textbook of radiology, 7th edition, volume 1 page 713 Mercedes Benz sign/Seagull sign/Crow feet sign:Gall bladder stone if radiopaque has a stellate faceted appearance with gas containing fissures on the plain radiograph and is called as Mercedes Benz sign/Seagull sign or Crowr feet sign', 'role': 'assistant'}]