This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: G.I.T, Subject name: Anatomy
Mercedes Benz sign or seagull sign is seen in 
Select and explain. 
A. Gall stones, B. Renal stones, C. CBD stones, D. Hydatid cyst
A: Gall stones
Answer: A: Gall stones 
Explanation: Mercedes Benz sign or Seagull sign The Centre of gallstone may contain radiolucent gas in a triradiate or biradiate fissure This gives rise to characteristic dark shapes on radiograph, the Mercedes Benz sign or Seagull sign Ref: Bailey and love 27th edition Pgno : 1199