Final answer:
ADH regulates blood pressure, increases water reabsorption in the kidneys, and stimulates vasoconstriction.
Step-by-step explanation:
Angiotensin II is a powerful vasoconstrictor that increases blood pressure. It also stimulates the release of ADH and aldosterone, which increase water reabsorption in the kidneys and stimulate vasoconstriction. Therefore, options A, B, and C are all true about ADH.