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
Which is the screening test for evaluation of mineralocoicoid excess? 
Select and explain. 
A. Saline infusion test, B. Salt loading test, C. Cosyntropin test, D. Aldosterone renin ratio
D: Aldosterone renin ratio
Answer: D: Aldosterone renin ratio 
Explanation: The accepted screening test for mineralocoicoid excess is aldosterone renin ratio. Since the leading cause is Adrenal Adenoma, the autonomous aldosterone values will rise and renin values will be low due to feedback. ARR screening is positive if ratio is > 750pmol/L per ng/ml. Spironolactone should be discontinued for at-least 4 weeks before performing this test for obvious reasons. This is followed by performance of investigation of choice for mineralocoicoid excess which is Saline infusion test.