This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
80 % of gall stones contain 
Select and explain. 
A. Bile pigments, B. Cholesterol, C. Calcium salts, D. Phospolipids
B: Cholesterol
Answer: B: Cholesterol 
Explanation: Answer- B. CholesterolTypes of gall stones-1. CholesterolPure cholesterol (10%)Mixed (70%)2. PigmentBlack pigment stonesBrown pigment stones