Correct Option: A

In vertebrate anatomy the pituitary gland is an endocrine gland about the size of a pea and weighing 0.5 grams (0.018 oz) in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain, and rests in a small, bony cavity covered by a dural fold. The pituitary gland secretes nine hormones that regulate homeostasis.