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: Medicine
Menkes kinky hair disease is due to deficiency of : 
Select and explain. 
A. Copper, B. Iodine, C. Iron, D. Selenium
A: Copper
Answer: A: Copper 
Explanation: Menkes disease is an X - linked disorder due to deficiency of Copper.