**Core Concept**
Conn's syndrome, also known as primary aldosteronism, is a condition characterized by excessive production of aldosterone, a hormone produced by the adrenal glands that regulates electrolyte balance and blood pressure. The underlying pathophysiology involves an overactive adrenal gland, leading to hyperaldosteronism.

**Why the Correct Answer is Right**
The correct answer is associated with Conn's syndrome because it directly relates to the excessive production of aldosterone, a key component of this condition. Aldosterone stimulates the kidneys to retain sodium and water, leading to increased blood pressure and volume. This is mediated through the mineralocorticoid receptor, which is activated by aldosterone. The excessive aldosterone production in Conn's syndrome can be caused by a variety of factors, including a benign adrenal adenoma, adrenal hyperplasia, or familial forms of the condition.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not directly relate to the pathophysiology of Conn's syndrome. While it may be associated with other endocrine disorders, it is not the primary cause of Conn's syndrome.
**Option B:** This option is incorrect because it refers to a different condition altogether. Cushing's syndrome is a condition characterized by excessive production of cortisol, not aldosterone.
**Option C:** This option is incorrect because it is not directly related to Conn's syndrome. While it may have some clinical features in common with Conn's syndrome, it is not the primary cause of the condition.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that Conn's syndrome can be caused by a variety of factors, including benign adrenal adenomas, adrenal hyperplasia, and familial forms of the condition. A high index of suspicion and careful clinical evaluation are necessary to diagnose this condition.

**Correct Answer: B. Cushing's syndrome is a condition characterized by excessive production of cortisol, not aldosterone.**