**Core Concept**
The adrenal medulla is a part of the sympathetic nervous system, responsible for the release of catecholamines (epinephrine, norepinephrine, and dopamine) into the bloodstream in response to stress or excitement. This occurs through the process of exocytosis, where vesicles containing the catecholamines fuse with the plasma membrane and release their contents.

**Why the Correct Answer is Right**
The adrenal medulla is primarily responsible for secreting epinephrine (adrenaline), norepinephrine (noradrenaline), and a small amount of dopamine. These hormones play a crucial role in the body's "fight or flight" response, increasing heart rate, blood pressure, and energy levels. The secretion of epinephrine and norepinephrine is mediated by the enzyme phenylethanolamine N-methyltransferase (PNMT), which is specific to the adrenal medulla.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, but we can proceed with the rest.
**Option B:** Incorrect because the adrenal medulla does not secrete antidiuretic hormone (ADH), which is produced by the hypothalamus and released by the posterior pituitary gland.
**Option C:** Incorrect because the adrenal medulla does not secrete aldosterone, which is secreted by the zona glomerulosa of the adrenal cortex.
**Option D:** Incorrect because the adrenal medulla does not secrete cortisol, which is secreted by the zona fasciculata of the adrenal cortex.

**Clinical Pearl / High-Yield Fact**
The adrenal medulla is unique in that it is the only part of the adrenal gland that is derived from neural crest cells, rather than mesoderm. This is reflected in its ability to synthesize and secrete catecholamines.

**Correct Answer:** B. ADH