A nurse is reviewing the serum laboratory findings for a client who has hypertension and is prescribed hydrochlorothiazide. Which of the following findings should the nurse report to the provider?

Choice A reason: A chloride level of 99 mEq/L is within the normal range (98–106 mEq/L) and does not require intervention. Choice B reason: A calcium level of 10 mg/dL is within the normal range (8.5–10.5 mg/dL) and is not concerning in this context. Choice C reason: A potassium level of 3.0 mEq/L is below the normal range (3.5–5.0 mEq/L). Hypokalemia is a known side effect of hydrochlorothiazide and can lead to cardiac arrhythmias. This finding should be reported promptly. Choice D reason: A sodium level of 136 mEq/L is within the normal range (135–145 mEq/L) and does not require immediate action.