Final answer:
Potassium-sparing diuretics specifically work in the distal convoluted tubule of the kidney, where they interfere with the sodium/potassium exchange.
Step-by-step explanation:
Potassium-sparing diuretics work by interfering with the sodium/potassium exchange in the kidneys, specifically affecting parts of the nephron involved in electrolyte balance. Among the options provided, potassium-sparing diuretics have their effect primarily in the distal convoluted tubule and possibly the collecting ducts, where they prevent the loss of potassium and counter the reabsorption of sodium. This distinct mechanism of action differentiates them from loop diuretics, which act on the ascending limb of the loop of Henle, and from thiazide diuretics, which also work in the distal convoluted tubule but have a slightly different mode of action.