**Core Concept**
Enalapril, an angiotensin-converting enzyme (ACE) inhibitor, is used to treat essential hypertension by blocking the conversion of angiotensin I to angiotensin II, a potent vasoconstrictor. This action leads to vasodilation and decreased peripheral resistance, resulting in lowered blood pressure.

**Why the Correct Answer is Right**
The correct answer is related to the mechanism of action of enalapril. ACE inhibitors like enalapril are known to increase the levels of bradykinin and other vasodilatory peptides, which contribute to the antihypertensive effect. Additionally, ACE inhibitors can also reduce aldosterone levels, leading to a decrease in sodium reabsorption and water retention. This results in increased excretion of sodium and water, further contributing to blood pressure reduction.

**Why Each Wrong Option is Incorrect**
**Option A:** Enalapril does not act by stimulating the release of renin, which is a key enzyme in the renin-angiotensin-aldosterone system. In fact, ACE inhibitors can lead to a decrease in renin release due to decreased angiotensin II levels.
**Option B:** Enalapril does not act by increasing the levels of angiotensin II, which is a potent vasoconstrictor. Instead, it blocks the conversion of angiotensin I to angiotensin II, leading to vasodilation and decreased blood pressure.
**Option C:** Enalapril does not act by increasing the levels of beta-blockers, which are a different class of antihypertensive medications. ACE inhibitors like enalapril work by a distinct mechanism that involves the blockade of ACE.

**Clinical Pearl / High-Yield Fact**
ACE inhibitors like enalapril are particularly useful in patients with heart failure and hypertension due to their ability to reduce afterload and improve cardiac output. Additionally, ACE inhibitors have been shown to have a protective effect on the kidneys by reducing proteinuria and slowing the progression of renal disease.

**Correct Answer:**