This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Vitamins and Minerals, Subject name: Biochemistry
Which of the following protein has ferroxidase activity? 
Select and explain. 
A. Albumin, B. Ceruloplasmin, C. Haptoglobin, D. Transferrin
B: Ceruloplasmin
Answer: B: Ceruloplasmin 
Explanation: Ceruloplasmin:- Copper-containing ferroxidase. Oxidizes toxic ferrous iron to its non-toxic ferric iron in the serum. This facilitates the transpo of iron by transferrin. This is why aceruloplasminemia leads to hemochromatosis. - Hephaestin is also a copper-dependent ferroxidase that oxidizes ferrous iron to ferric. It works in cooperation with ferropoin in the cells.