This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Lipoproteins, Subject name: Biochemistry
The source of apo-E and apo C-II for the chylomicrons is: 
Select and explain. 
A. VLDL, B. IDL, C. LDL, D. HDL
D: HDL
Answer: D: HDL 
Explanation: Newly secreted or "nascent" chylomicrons and ApoB-48 apolipoprotein. HDL acts as a reservoir of lipoproteins and provide ApoE and ApoC to nascent chylomicrons to form mature chylomicrons.