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
Proteins which is having DNA binding domain in its structure 
Select and explain. 
A. Zinc finger, B. Helix-turn-helix, C. Leucine zipper, D. All of these
D: All of these
Answer: D: All of these 
Explanation: None