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
Leucine-Zipper complex is 
Select and explain. 
A. DNA binding protein, B. Membrane attack complex, C. B cell epitomes, D. Receptor ligand protein
A: DNA binding protein
Answer: A: DNA binding protein 
Explanation: None