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
Percentage of gallstones that are radio opaque 
Select and explain. 
A. 10%, B. 20%, C. 30%, D. 40%
A: 10%
Answer: A: 10% 
Explanation: Most (upto 90%)of gall stones are radio lucent Upto 10% of gallstones are radio opaque Ref: Bailey and love 27th edition Pgno : 1121 Most(upto 90%) kidney stones are radio opaque