A nurse is caring for a client that will receive a diuretic for fluid overload. Which of the following diuretics act on the loop of Henle?

The correct answer is C: Furosemide. Furosemide is a loop diuretic that acts on the ascending loop of Henle to inhibit sodium and chloride reabsorption, leading to increased urine output. Spironolactone (A) is a potassium-sparing diuretic that acts on the distal tubule. Hydrochlorothiazide (B) is a thiazide diuretic that acts on the distal convoluted tubule. Mannitol (D) is an osmotic diuretic that works in the proximal tubule and descending loop of Henle. The other choices do not specifically target the loop of Henle for diuretic action.