This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Disorders of Adrenal Gland, Subject name: Medicine
[{'content': 'Which is least likely to be elevated in patients with a pheochromocytoma? \nSelect and explain. \nA. Systemic aerial diastolic pressure, B. Systemic aerial systolic pressure, C. Serum norepinephrine, D. Intravascular volume', 'role': 'user'}, {'content': 'Answer: D \nExplanation: Pheochromocytoma is producing Nor epinephrine & Epinephrine which increases the systolic and diastolic pressure. * Also Nor epinephrine would be higher D/T extreme vasoconstriction the intravascular volume of the patient will be significantly reduced and not elevated.', 'role': 'assistant'}]