Atrial natriuretic factor is a peptide hormone which decreases blood pressure . It causes dilation of blood vessels and thus reduces blood pressure .Hence opt 2 is correct . Clearly mentioned in 11th NCERT pg no. 337

Decrease in blood pressure/volume and its effect on hormone release:

When blood pressure or blood volume decreases, the body initiates a series of physiological responses to restore homeostasis. These responses involve the release of various hormones that help regulate blood pressure and volume. However, one of these hormones is not released in response to a decrease in blood pressure/volume.

(1) Renin:
Renin is an enzyme released by the kidneys in response to low blood pressure or decreased blood volume. Its release is stimulated by various factors such as sympathetic nervous system activation, decreased sodium delivery to the distal tubules of the kidney, and decreased renal perfusion pressure. Renin plays a crucial role in the renin-angiotensin-aldosterone system (RAAS), which regulates blood pressure. It catalyzes the conversion of angiotensinogen into angiotensin I, which is subsequently converted to angiotensin II. Angiotensin II causes vasoconstriction, stimulates the release of aldosterone, and promotes water and sodium reabsorption, all of which help raise blood pressure.

(2) Atrial natriuretic factor (ANF):
Atrial natriuretic factor, also known as atrial natriuretic peptide (ANP), is released by the atria of the heart in response to increased blood volume or stretch. Its release is stimulated by factors such as atrial distension and increased atrial pressure. ANF acts to counteract the effects of the renin-angiotensin-aldosterone system. It promotes vasodilation, increases urinary sodium and water excretion, and inhibits the release of renin, aldosterone, and ADH. These actions help decrease blood volume and pressure.

(3) Aldosterone:
Aldosterone is a hormone released by the adrenal glands in response to low blood pressure or decreased blood volume. Its release is stimulated by angiotensin II and the increased activity of the RAAS. Aldosterone acts on the distal tubules and collecting ducts of the kidneys, promoting the reabsorption of sodium and the excretion of potassium. This leads to an increase in blood volume and blood pressure.

(4) ADH:
Antidiuretic hormone (ADH), also known as vasopressin, is released by the posterior pituitary gland in response to low blood pressure or decreased blood volume. Its release is regulated by the hypothalamus and is stimulated by factors such as increased plasma osmolality and decreased blood volume. ADH acts on the kidneys, promoting water reabsorption in the collecting ducts. This results in decreased urine volume and helps restore blood volume and pressure.

Conclusion:
In summary, when blood pressure/volume decreases, the body releases renin, aldosterone, and ADH to restore homeostasis. However, the release of atrial natriuretic factor (ANF) is not triggered by a decrease in blood pressure/volume. ANF is released in response to increased blood volume or stretch, and it acts to counteract the effects of the renin-angiotensin-aldosterone system, promoting vasodilation and increased urinary sodium and water excretion.