This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Circulation, Subject name: Physiology
[{'content': 'Following was the data obtained from a patient:- Aerial BP = 90 mm Hg, cardiac output = 5.4 L/min. How much is the peripheral resistance? \nSelect and explain. \nA. 1 R, B. 2 R, C. 4 R, D. 6 R', 'role': 'user'}, {'content': "Answer: A \nExplanation: By Ohm's law: Cardiac output (Q) = aerial BP/ peripheral resistance (R). Therefore, R = BP/CO Unit for peripheral resistance is PRU. 1 PRU = 1 mm Hg/mL/sec. That is, 1 PRU is 1 mm Hg when flow at the root of the aoa is 1 mL/sec. Thus, the unit for cardiac output will have to be conveed to mL/sec. 5.4 L/min = 90 mL/sec. Peripheral resistance (PRU) = 90 mm Hg/90 mL per sec. = 1 R.", 'role': 'assistant'}]