**Core Concept**
Atrial Natriuretic Peptide (ANP) is a hormone secreted by the atria of the heart in response to increased stretch and pressure. It plays a crucial role in regulating blood pressure and fluid balance by promoting the excretion of sodium and water.

**Why the Correct Answer is Right**
ANP causes vasodilation of blood vessels, particularly in the pulmonary and renal circulations, leading to a decrease in blood pressure. This results in increased sodium excretion by the kidneys, which in turn reduces fluid volume and blood pressure. ANP also inhibits the release of renin and aldosterone, further contributing to its blood pressure-lowering effects.

**Why Each Wrong Option is Incorrect**
**Option A:** Increased thirst and ADH release - This is incorrect because ANP actually inhibits the release of antidiuretic hormone (ADH), which would increase water reabsorption in the kidneys.

**Option B:** Increased vascular resistance - This is incorrect because ANP causes vasodilation, which decreases vascular resistance.

**Option C:** Increased aldosterone release - This is incorrect because ANP inhibits the release of aldosterone, which would increase sodium reabsorption in the kidneys.

**Clinical Pearl / High-Yield Fact**
ANP is often used as a biomarker for heart failure, as its levels are elevated in conditions where there is increased atrial stretch and pressure.

**Correct Answer:** D. Vasodilation and increased sodium excretion.