A nurse is caring for a client who has a prescription for potassium chloride (KCL) 20 mEq PO daily. The nurse reviews the client's most recent laboratory results and finds the client's potassium level is 6.0 mEq/L. Which of the following actions should the nurse take?

The correct answer is B: Call the prescribing physician and inform her of the client's serum potassium level results. This action is necessary because the client's potassium level is high (6.0 mEq/L), indicating hyperkalemia, which can lead to serious complications such as cardiac arrhythmias. The physician needs to be informed so she can reassess the prescription and decide on the appropriate course of action, which may include adjusting the dose or discontinuing KCL. Option A is incorrect because administering KCL in this scenario can worsen hyperkalemia. Option C is unnecessary as the nurse already has the lab results. Option D is incorrect as it does not address the high potassium level.