A nurse is caring for a group of toddlers receiving digoxin therapy. For which of the following toddlers should the nurse revise the plan of care?

A. A normal apical pulse for a toddler is around 90-140 beats per minute. This toddler's heart rate is within normal range. B. This toddler's potassium level is within the normal range. C. This toddler's digoxin level is within the therapeutic range. D. Vomiting can be a sign of digoxin toxicity. Digoxin has a narrow therapeutic index, meaning that even small increases in the drug level can lead to toxicity.