This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Bio-Chemistry), Subject name: Biochemistry
[{'content': 'Which one of the following are metalloporphyrins \nSelect and explain. \nA. Cytochrome, B. Hemoglobin, C. Bilirubins, D. Catalase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: (A) Cytochrome # Metalloporphyrins: Heme is the most important part of the metalloporphyrins Heme Chlorophyll Cytochromes Catalase Tryptophan pyrrolase', 'role': 'assistant'}]