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: Pharmacology
[{'content': 'The rate of injection of intravenous Valium is: \nSelect and explain. \nA. 1 ml / min, B. 2.5 ml / min, C. 1 mg / min, D. 2.5 mg / min', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]