The correct answer is option 1 - Adrenal gland. The adrenal glands, which are located on top of the kidneys, play a significant role in regulating blood pressure. These glands produce hormones called catecholamines, such as adrenaline and noradrenaline, which can increase blood pressure. Adrenaline acts by stimulating the heart to beat faster and stronger, while noradrenaline constricts blood vessels, thus increasing the resistance to blood flow and raising blood pressure. In addition to catecholamines, the adrenal glands also produce aldosterone, a hormone that helps regulate salt and water balance in the body. By controlling the fluid levels, aldosterone indirectly affects blood pressure. Therefore, the adrenal glands play a crucial role in maintaining blood pressure within normal limits.