## **Core Concept**
The patient's presentation suggests **primary aldosteronism**, also known as Conn's syndrome, characterized by hypertension, hypokalemia, metabolic alkalosis, and low plasma renin activity. This condition is often caused by an **aldosterone-producing adenoma** in the adrenal gland, which is consistent with the finding of a mass on the left suprarenal gland.

## **Why the Correct Answer is Right**
The symptoms and laboratory findings in this patient are consistent with primary aldosteronism due to an aldosterone-producing adenoma. The likely prescribed drug is **spironolactone**, a **potassium-sparing diuretic** and **aldosterone antagonist**. Spironolactone works by blocking the effects of aldosterone on the collecting ducts of the kidneys, leading to decreased sodium reabsorption and decreased potassium excretion. This results in reduced blood pressure, correction of hypokalemia, and resolution of metabolic alkalosis. The effectiveness of spironolactone in managing the patient's symptoms and laboratory abnormalities supports this diagnosis.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is blank and cannot be evaluated.
- **Option B:** This option is blank and cannot be evaluated.
- **Option C:** This option is blank and cannot be evaluated.
- **Option D:** This option is blank and cannot be evaluated.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that **spironolactone** is often used as a therapeutic trial for patients suspected of having primary aldosteronism. The effectiveness of spironolactone can help confirm the diagnosis. Additionally, spironolactone is known for its anti-androgenic side effects, such as **gynecomastia**.

## **Correct Answer Line**
**Correct Answer: C. Spironolactone**