A nurse is preparing to administer verapamil by IV bolus to a client who is having cardiac dysrhythmias. For which of the following adverse effects should the nurse monitor when giving this medication?

The correct answer is D: Hypotension. Verapamil is a calcium channel blocker that can cause hypotension as a common adverse effect by decreasing blood pressure. This is crucial to monitor as it can lead to serious complications such as dizziness, fainting, or even shock. Hyperthermia (A), muscle pain (B), and ototoxicity (C) are not commonly associated with verapamil administration. Monitoring for hypotension is essential for the nurse to ensure the client's safety and well-being during the administration of verapamil.