Select the correct statement.

Reduction in glomerular filtration rate activates JG cells to release renin. Reduction in glomerular filtration rate (GFR) activates the juxtaglomerular (JG) cells located in the walls of the afferent arterioles. The JG cells respond to the reduced GFR by releasing the enzyme renin, initiating the renin-angiotensin-aldosterone system. This leads to vasoconstriction and other physiological responses to increase blood pressure to restore GFR to normal level. 

(1) Angiotensin II is a potent vasoconstrictor, not a vasodilator. It constricts blood vessels, increasing blood pressure.

(2) The vasa recta, specialised capillaries associated with Henle’s loop, exhibit a countercurrent pattern of blood flow. This pattern allows for the exchange of solutes and water between the descending and ascending limbs of the vasa recta, aiding in the establishment and maintenance of the concentration gradient in the kidney medulla. 

(4) ANF is a hormone released by the heart in response to increased blood volume and pressure. It acts as a vasodilator and promotes the excretion of sodium and water by the kidneys, leading to a decrease in blood pressure.