The nurse is caring for a child with Acute Renal Failure. Which clinical manifestation would the nurse recognize as a sign of hyperkalemia?

A. Oliguria (reduced urine output) is a common sign of acute renal failure but is not directly related to hyperkalemia. B. Seizures can be a consequence of severe electrolyte imbalances, but cardiac arrhythmia is a more specific sign of hyperkalemia. C. Cardiac arrhythmias are a key indicator of hyperkalemia, as elevated potassium levels can affect the electrical conduction system of the heart. D. Dyspnea (difficulty breathing) may result from other complications of acute renal failure but is not specifically linked to hyperkalemia.