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': 'Which of the following is the role of coenzyme Q (ubiquinone) in the respiratory chain? \nSelect and explain. \nA. It links flavoproteins to cytochrome b, the cytochrome of lowest redox potential, B. It links NAD-dependerit dehydrogenases to cytochrome b, C. It links each of the cytochromes in the respiratory chain to one another, D. It is the first step in the respiratory chain', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Coenzyme Q collects reducing equivalents from flavoprotein complexes and passes them along the chain to the cytochromes. Reducing equivalents from a number of substrates are passed through coenzyme Q in the respiratory chain.', 'role': 'assistant'}]