What side effect of diuretic therapy should the client be told to watch out for that can lead to a life-threatening emergency? a. Low blood pressure. b. Constipation c. Lethargy. d. Muscle weakness or leg cramps.

The correct answer is d. Muscle weakness or leg cramps.<br /><br />Diuretic therapy can cause electrolyte imbalances, particularly hypokalemia (low potassium levels), which can lead to muscle weakness or leg cramps. This can be a life-threatening emergency if not managed properly. It is important for clients on diuretic therapy to be aware of this potential side effect and to report any symptoms of muscle weakness or cramping to their healthcare provider immediately.