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
Which of the following plays an important role in retinol mobilization? 
Select and explain. 
A. Zinc, B. Iron, C. Manganese, D. Magnesium
A: Zinc
Answer: A: Zinc 
Explanation: Zinc plays an important role in retinol mobilization.