T.T.K.G >8 is seen in all except:

Transtubular potassium gradient > 8 is associated with hyperkalemia. Choices 1, 2, 3 lead to hyperkalemia. Choices 1 and 2 lead to kidney damage. Choice 3 due to aldosterone deficiency leads to potassium excess due to inability to loose potassium the collecting duct. Cushing syndrome has excess of coisol, which stimulates the mineralocoicoid receptors to cause hypokalemic metabolic alkalosis.