Final answer:
Diuretics are used to treat high blood pressure as they increase urine output and reduce blood volume, leading to a decrease in blood pressure. They inhibit the reabsorption of Na+ and Cl- in the kidneys, but don't address the underlying cause of hypertension.
Step-by-step explanation:
Diuretics are used to treat chronic high blood pressure (hypertension) because they decrease blood volume by increasing urine output. This is option (c). The increased urine volume occurs because diuretics inhibit the reabsorption of sodium (Na+) and chloride (Cl-) ions, which leads to a subsequent loss of water due to osmosis. Popular diuretics, like hydrochlorothiazide, work on the Distal Convoluted Tubule (DCT) and collecting duct of the nephron in the kidney, inhibiting the Nat/Cl symporter, resulting in increased Na+ and water excretion. This reduction in blood volume subsequently decreases blood pressure. Although diuretics help manage the effects of high blood pressure, they do not directly target the root cause of hypertension.