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
Apoprotein of cholesterol is: 
Select and explain. 
A. Apo Al, B. ApoA2, C. Apo Cl, D. ApoE
D: ApoE
Answer: D: ApoE 
Explanation: Apolipoprotein E is a plasma protein that serves as a ligand for low density lipoprotein receptors and, through its interaction with these receptors, paicipates in the transpo of cholesterol and other lipids among various cells of the body.