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: Physiology
Which is a heme protein ? 
Select and explain. 
A. Hemoglobin, B. Catalase, C. Cytochrome, D. All of the above
D: All of the above
Answer: D: All of the above 
Explanation: Ans. is 'd' i.e., All of the above Hemoproteins are proteins which have heme as prosthetic group. Impoant hemoproteins are hemoglobin, myoglobin, cytochromes (cytochrome C, cytochrome P450),catalase, peroxidase, tryptophan pyrrolase and nitric oxide synthase.