Which of the following results can be expected after the administration of ACE inhibitor medication?

The administration of an ACE inhibitor is primarily associated with the decrease in blood pressure. ACE inhibitors work by blocking the action of angiotensin-converting enzyme, which plays a crucial role in the renin-angiotensin-aldosterone system (RAAS). When this enzyme is inhibited, the production of angiotensin II is reduced. Angiotensin II is a potent vasoconstrictor, and its reduction leads to the relaxation of blood vessels, resulting in lower systemic vascular resistance and consequently a decrease in blood pressure.

In addition to reducing blood pressure, ACE inhibitors also promote mild diuresis, decrease levels of aldosterone, and affect how the kidneys handle sodium and potassium. This mechanism helps to explain why fluid retention decreases rather than increases, as the body tends to excrete excess fluid when blood pressure lowers. Therefore, the primary expected result of ACE inhibitor administration is the lowering of blood pressure, making this the correct answer.