**Core Concept**
Excessive mineralocorticoid action can lead to various adverse effects due to its role in regulating electrolyte balance and blood pressure. Mineralocorticoids, such as aldosterone, stimulate the kidneys to retain sodium and water, while promoting the excretion of potassium. This can disrupt the delicate balance of electrolytes in the body, leading to several complications.

**Why the Correct Answer is Right**
The correct answer is related to the effects of excessive mineralocorticoid action on the body. Mineralocorticoids can cause hypertension, hypokalemia, and metabolic alkalosis due to their role in sodium retention and potassium excretion. Additionally, they can lead to cardiac hypertrophy and arrhythmias due to the increase in blood pressure.

**Why Each Wrong Option is Incorrect**
* **Option A:** This is incorrect because excessive mineralocorticoid action can indeed cause hypertension, which is a well-known adverse effect.
* **Option B:** This is incorrect because hypokalemia (low potassium levels) is a direct consequence of excessive mineralocorticoid action, which promotes potassium excretion in the urine.
* **Option C:** This is incorrect because metabolic alkalosis is a common complication of excessive mineralocorticoid action, which can lead to an increase in blood pH.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the effects of excessive mineralocorticoid action can be reversed by spironolactone, a potassium-sparing diuretic that blocks the action of aldosterone. This is a useful clinical correlation to keep in mind when managing patients with hypertension or hypokalemia.

**Correct Answer: C.**