A nurse is assessing a client with profuse vomiting and diarrhea. Which finding is a manifestation of hypokalemia?

The correct answer is B: Muscle weakness. Hypokalemia, a low potassium level, can lead to muscle weakness due to impaired muscle function. Potassium is essential for proper muscle contraction, so a deficiency can result in weakness. Hyperactive bowel sounds (A) are more indicative of hyperkalemia, not hypokalemia. Increased thirst (C) is a symptom of dehydration, which can result from vomiting and diarrhea but is not specific to hypokalemia. Cerebral edema (D) is not a typical manifestation of hypokalemia.