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
Cholesterol is: 
Select and explain. 
A. Tocopherol, B. Lipoprotein, C. Steroid, D. Lipopolysacchride
C: Steroid
Answer: C: Steroid 
Explanation: 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.