The correct answer is option 1, brain. The pituitary gland, also known as the master gland, is a small pea-sized gland situated at the base of the brain, in an area called the sella turcica. It is often referred to as the "control center" of the endocrine system because it produces and releases hormones that regulate various bodily functions. This gland consists of two main parts: the anterior pituitary and the posterior pituitary. The anterior pituitary produces hormones responsible for growth, metabolism, reproduction, and stress response, while the posterior pituitary stores and releases hormones related to water balance and lactation. Its location in the brain allows the pituitary gland to receive signals from the hypothalamus and send instructions to other endocrine glands throughout the body.