Answer:
The correct answer is - vasoconstrict due to angiotensin 2.
Explanation:
The low blood pressure activates the renin-angiotensin-aldosterone system in the kidneys. Renin is a hormone that results in the release and production of the angiotensin II that leads to the release of the aldosterone in kidney.
The angiotensin also causes the efferent arterioles that help to decrease in the GFR which helps in increasing the blood flow with the help of the aldosterone.
Thus, the correct answer is - vasoconstrict.