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
The most important role of cholesterol is: 
Select and explain. 
A. It is a component of cell membrane, B. It is a precursor of polyunsaturated fatty acids, C. It stores up energy, D. None of the above
A: It is a component of cell membrane
Answer: A: It is a component of cell membrane 
Explanation: None