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: Biochemistry
[{'content': 'Cyanide is toxic because it - \nSelect and explain. \nA. Inhibits cytochrome oxidase, B. Forms cyan meth Hb, C. Inhibits ATP carrier in mitochondria, D. Inhibits Na-K-ATP ase', 'role': 'user'}, {'content': 'Answer: A \nExplanation: A i.e. Inhibits Cytochrome oxidase', 'role': 'assistant'}]