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': 'A patient requires an infusion of procainamide. Its half-life is 2 hrs. The infusion is begun at 9 AM. At 1 PM on the same day, the blood concentration is found to be 3 mg/L. What is the probable steady-state concentration after 2 days of infusion? \nSelect and explain. \nA. 3 mg/L, B. 4 mg/L, C. 6 mg/L, D. 15 mg/L', 'role': 'user'}, {'content': 'Answer: B \nExplanation: None', 'role': 'assistant'}]