This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Respiratory Chain, Subject name: Biochemistry
[{'content': 'Cytochrome oxidase contains \nSelect and explain. \nA. Ca++, B. Cu, C. Mn, D. Zn', 'role': 'user'}, {'content': "Answer: B \nExplanation: (CU) (76 - Lippincott's) (104 - HP 27th)Cytochrome oxidase (cytochroe a + a3) contains bound copper atoms, that are required for this complex reaction to occur", 'role': 'assistant'}]