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: Biochemistry
[{'content': 'Cholesterol is: \nSelect and explain. \nA. Tocopherol, B. Lipoprotein, C. Steroid, D. Lipopolysacchride', 'role': 'user'}, {'content': 'Answer: C \nExplanation: Cholesterol is an amphipathic lipid and is an impoant structural component of membranes and of the outer layer of plasma lipoproteins. It is mainly synthesized in many tissues from Acetyl-CoA and is the precursor of all other steroids in the body, including coicosteroids, sex hormones, bile acids, and vitamin D.', 'role': 'assistant'}]