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': 'A 56-year old woman has a mean systemic blood pressure of 100 mm Hg and a resting cardiac output of 4 L/min. What is the total peripheral resistance of this woman? \nSelect and explain. \nA. 0.025 mL/min/mm Hg, B. 0.025 mm Hg/mL/min, C. 40 mL/min/mm Hg, D. 40 mm Hg/min/mL', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Total peripheral resistance (TPR) is equal to the pressure gradient across the circulation (mean aerial pressure - right atrial pressure) divided by the cardiac output. Right atrial pressure is assumed to equal 0 mm Hg. Thus, TPR = 100/4000 = 0.025 mm Hg/mL/min. The "ABC rule" is useful in remembering the relation between pressure (P), flow (Q), and resistance (R) because P=QR (P,Q and R in alphabetical order). Tip: Note that choices A, C, & D can be eliminated quickly because in each case the units are incorrect.', 'role': 'assistant'}]