Final answer:
One manifestation of digoxin toxicity is bradycardia, which is a slow heart rate.
Step-by-step explanation:
The nurse should include bradycardia as a manifestation of digoxin toxicity when teaching the client. Digoxin, a medication commonly used to treat heart conditions, can cause toxicity at higher levels, leading to various symptoms. Bradycardia, or a slow heart rate, is one of the manifestations of digoxin toxicity.