This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Metabolism of lipid, Subject name: Biochemistry
Primary bile acid is 
Select and explain. 
A. Deoxycholic acid, B. Lithocholic acid, C. Chenodeoxycholic acid, D. None
C: Chenodeoxycholic acid
Answer: C: Chenodeoxycholic acid 
Explanation: Bile acids are formed from cholesterol. Types:(a) Primary bile acids: They are synthesized in the liver from cholesterol. They are mainly two:Cholic acid: Quantitatively the largest in an amount in bile.Chenodeoxycholic acid.(b) Secondary bile acids: They are produced in the intestine from the primary bile acids by the action of intestinal bacteria, they are produced by deconjugation and 7-a-dehydroxylation. They are mainly two:Deoxycholic acid: Formed from cholic acid.Lithocholic acid: Formed from chenodeoxycholic acid.Ref: Harper&;s Biochemistry; 30th edition