**Core Concept**
The posterior pituitary is a specialized neurohemal junction that stores and releases hormones synthesized in the hypothalamus. Antidiuretic hormone (ADH), also known as vasopressin, plays a crucial role in water balance and electrolyte homeostasis in the body.

**Why the Correct Answer is Right**
ADH is synthesized in the hypothalamus, specifically in the supraoptic and paraventricular nuclei. The synthesized ADH is then transported down the axons of hypothalamic neurons to the posterior pituitary, where it is stored in secretory vesicles and released into the bloodstream in response to increased plasma osmolality or decreased blood volume. This release of ADH stimulates the kidneys to reabsorb water, increasing the concentration of the urine and conserving body water.

**Why Each Wrong Option is Incorrect**
**Option A:** The anterior pituitary is responsible for releasing hormones such as growth hormone, prolactin, and adrenocorticotropic hormone (ACTH), but it does not release ADH.
**Option C:** While the hypothalamus synthesizes ADH, it is not the primary site of ADH release. The hypothalamus acts as the central regulator of ADH release, but the posterior pituitary is the site of actual hormone secretion.
**Option D:** There is no such thing as the "intermediate pituitary." The pituitary gland is divided into two main parts: the anterior pituitary and the posterior pituitary.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the posterior pituitary is a unique neurohemal junction that stores and releases hormones synthesized in the hypothalamus. This distinction is crucial in understanding the regulation of various hormones, including ADH, and their effects on the body.

**✓ Correct Answer: B. Posterior pituitary**