A nurse is assessing a client who has heart failure and is prescribed furosemide. Which of the following findings is an adverse effect of this medication?

The correct answer is A: Hypokalemia. Furosemide is a loop diuretic that works by increasing the excretion of water and electrolytes, including potassium. This can lead to hypokalemia, which is a common adverse effect. Hypoglycemia (B) is not directly associated with furosemide. Weight gain (C) is not an adverse effect but rather a potential improvement in heart failure symptoms due to decreased fluid overload. Increased blood pressure (D) is not an expected adverse effect of furosemide; instead, it typically helps reduce blood pressure.