Final answer:
The posterior pituitary gland releases the antidiuretic hormone (ADH). This hormone, which is produced in the hypothalamus, helps regulate water balance by increasing water reabsorption in the kidneys. The correct option is c.
Step-by-step explanation:
The structure that releases the antidiuretic hormone (ADH), also known as vasopressin, is the posterior pituitary gland. ADH is produced in the hypothalamus and then transported to the posterior pituitary where it is stored until it is needed.
The main function of ADH is to regulate the body's water balance by controlling the amount of water reabsorbed by the kidneys from the collecting ducts. When the body needs to conserve water, ADH is released into the bloodstream and travels to the kidneys.
There, it increases the permeability of the collecting ducts, allowing more water to be reabsorbed back into the blood, reducing urine volume and maintaining hydration. Option c. is the correct one.