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: Physiology
[{'content': 'In a patient with Cardiac output 5 litre/min and body surface area 1.7 square metre, what will be the cardiac index? \nSelect and explain. \nA. 3 l/min/sq. m, B. 4 l/min/sq. m, C. 5 l/min/sq. m, D. 2.5 l/min/sq. m', 'role': 'user'}, {'content': 'Answer: A \nExplanation: None', 'role': 'assistant'}]