Which of the following best describes Lisinopril's mechanism of action?

Lisinopril operates primarily as an ACE inhibitor, which stands for Angiotensin-Converting Enzyme inhibitor. By inhibiting ACE, Lisinopril reduces the conversion of angiotensin I to angiotensin II, a hormone that can increase blood pressure and stimulate the release of aldosterone from the adrenal glands. This decrease in angiotensin II results in vasodilation, reduced blood pressure, and decreased workload on the heart.

Option B accurately captures Lisinopril's mechanism of action as it competes with the enzyme to block the production of angiotensin II, leading to the therapeutic effects commonly associated with ACE inhibitors, such as managing hypertension and heart failure.

Understanding that the other options do not accurately describe the mechanism of Lisinopril provides a clearer context. While aldosterone synthesis is affected as a secondary consequence of reduced angiotensin II, the primary action of Lisinopril is the inhibition of ACE itself. It does not directly increase cardiac output or inhibit sodium absorption in the intestines, which further clarifies why option B is the best choice.