**Core Concept**
Hyperkalemia is a condition characterized by elevated serum potassium levels, which can be life-threatening due to its effects on cardiac function and muscle excitability. Treatment aims to stabilize cardiac membranes, shift potassium into cells, and eliminate excess potassium from the body.

**Why the Correct Answer is Right**
Hyperkalemia is typically treated with medications that promote potassium entry into cells, such as insulin and beta-2 agonists, which activate cellular potassium uptake. Calcium gluconate is used to stabilize cardiac membranes and counteract the cardiac effects of hyperkalemia. Potassium-binding resins, like polystyrene sulfonate, can also be used to eliminate excess potassium from the body. However, potassium itself is not administered in the treatment of hyperkalemia, as it would further elevate serum levels.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it is not a treatment for hyperkalemia. Administering potassium would worsen the condition.
**Option B:** This option is incorrect because it is not a standard treatment for hyperkalemia. While calcium gluconate is used to stabilize cardiac membranes, administering potassium itself is not a treatment for hyperkalemia.
**Option C:** This option is incorrect because it is not a treatment for hyperkalemia. Administering potassium would further elevate serum levels and worsen the condition.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that potassium itself is not administered in the treatment of hyperkalemia, as it would worsen the condition. Instead, treatments focus on promoting potassium entry into cells, stabilizing cardiac membranes, and eliminating excess potassium from the body.

**Correct Answer: A. Potassium.**