This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Gall Bladder & Bile Ducts, Subject name: Surgery
[{'content': 'Percentage of Gall stones that are radiopaque are \nSelect and explain. \nA. 10-20%, B. 30-40%, C. 50-60%, D. 70-80%', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Ans. (a) 10-20%Ref: Bailey and Love 27th edition Page 1190* Plain X ray will show Radio opaque Gallstones- 10% of patients* Rarely the centre of stone may have Radiolucent Gas in Triradiate or Biradiate Fissure having dark shapes known as "Mercedes Benz Sign or Seagull Sign "* Porcelain Gallbladder is calcified gallbladder.', 'role': 'assistant'}]