**Core Concept**
The Syndrome of Apparent Mineralocorticoid Excess (SAME) is a rare genetic disorder characterized by excessive mineralocorticoid activity without an increase in aldosterone levels. This condition leads to sodium retention, potassium excretion, and hypertension due to the inappropriate activation of mineralocorticoid receptors.

**Why the Correct Answer is Right**
The correct answer is due to a deficiency of 11-beta hydroxysteroid dehydrogenase (11-beta HSD) type 2 enzyme. This enzyme is responsible for converting cortisol to cortisone, which is inert and cannot activate mineralocorticoid receptors. In the absence of 11-beta HSD type 2, cortisol can bind to mineralocorticoid receptors, mimicking the effects of aldosterone and leading to SAME. The enzyme deficiency results in a relative excess of cortisol, which is a potent mineralocorticoid.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not relate to the pathophysiology of SAME. The condition is not caused by a deficiency of aldosterone or its receptor.
* **Option B:** This option is incorrect because it is actually the enzyme responsible for converting cortisone to cortisol, not the enzyme deficient in SAME.
* **Option C:** This option is incorrect because it is not directly related to the pathophysiology of SAME. The condition is not caused by a deficiency of cortisol or its receptors.

**Clinical Pearl / High-Yield Fact**
The Syndrome of Apparent Mineralocorticoid Excess is a rare genetic disorder that can be challenging to diagnose. The condition is often associated with hypertension, hypokalemia, and metabolic alkalosis. A high level of cortisol in the urine can be a diagnostic clue, and genetic testing for the 11-beta HSD type 2 gene can confirm the diagnosis.

**Correct Answer:** D.