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 the best test for Conn syndrome? \nSelect and explain. \nA. Urinary metanephrines, B. Plasma aldosterone to renin ratio, C. Urinary electrolytes, D. Renal vein renin levels', 'role': 'user'}, {'content': "Answer: B \nExplanation: (IOC) Best test for Conn's syndrome: Salt-loading test/Saline infusion test Screening test: Plasma aldosterone renin ratio * In patient with conn's syndrome, the plasma aldosterone levels || d/t tumor which causes endogenous production of aldosterone Therefore, Aldosterone levels are elevated, the RAAS system has negative feedback so Plasma Renin activity reduces. So Aldosterone Renin Ratio (increased) Since, Plasma aldosterone increased (d/t tumor) & Plasma renin || Option D- Low renin levels are seen in Both Conn's & Liddle's syndrome so only renal vein renin levels alone cannot be helpful for diagnosis.", 'role': 'assistant'}]