Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R).

Assertion (A) : Both ADH and ANF mechanisms regulate the kidney function by raising the blood pressure.

Reason    (R)  : Both the hormones are secreted when there is loss of body fluids leading to low blood volume and pressure.

In light of the above statements, choose the correct answer from the options given below.

Both (A) and (R) are false. 

The assertion is false because ADH and ANF have opposite effects on blood pressure regulation. ADH, also known as vasopressin, increases water reabsorption in the kidneys, leading to an increase in blood volume and subsequently an increase in blood pressure. On the other hand, ANF acts as a vasodilator and promotes the excretion of sodium and water by the kidneys, which decreases blood volume and blood pressure.

The reason is also false because it inaccurately suggests that both ADH and ANF are secreted in response to low blood volume and pressure. While it is true that ADH is released in response to low blood volume or dehydration to conserve water and raise blood pressure, ANF is released in response to high blood volume and pressure to promote diuresis (increased urine production) and lower blood pressure.