This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Biosynthesis of Fatty Acids and Eicosanoids, Subject name: Biochemistry
[{'content': 'True about bile acids is? \nSelect and explain. \nA. 7a hydroxylase is the rate limiting enzyme in the synthesis, B. They are derived from cholesterol, C. Cholic acid is primary bile acid, D. All of the above', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Ans. (d) All of the aboveRef Harpers Biochemistry 28/e, chapter 26', 'role': 'assistant'}]