The correct answer is c atrial natriuretic peptide.
Atrial natriuretic peptide (ANP) is a hormone produced by the heart that helps lower blood pressure. It works by promoting the excretion of sodium and water by the kidneys, which decreases blood volume and, subsequently, blood pressure.
In contrast, aldosterone, norepinephrine, angiotensin II, and antidiuretic hormone (ADH) all contribute to increasing blood pressure. Aldosterone increases sodium reabsorption, norepinephrine causes vasoconstriction, angiotensin II is a potent vasoconstrictor, and ADH promotes water retention. Therefore, ANP is unique in its role as a promoter of lower blood pressure.