The statement indicates that the nurse's teaching about the purpose of an implanted cardioverter-defibrillator (ICD) has been successful?

An implanted cardioverter-defibrillator is designed for the automatic termination of lethal ventricular arrhythmias. The device continuously monitors the cardiac rhythm and delivers a high-energy synchronous or asynchronous shock to restore hemodynamic stability when it detects life-threatening ventricular tachycardia or ventricular fibrillation. A. While working on an alternator involves magnetic fields, avoiding it is a safety precaution rather than a statement about the "purpose" of the device. This reflects an understanding of environmental safety but does not demonstrate that the patient understands the clinical function of the ICD in managing their heart rhythm. B. Asking about the frequency of device checks is a procedural or follow-up question. While it shows the patient is engaged in their care, it does not provide evidence that they understand the physiological role of the ICD or why it was implanted in their body in the first place. C. Avoiding handheld security devices is a safety instruction related to electromagnetic interference (EMI). Like the alternator statement, this indicates knowledge of precautions but does not describe the core therapeutic goal of the device, which is the prevention of sudden cardiac death through internal defibrillation. D. This statement correctly identifies the primary therapeutic purpose of the ICD. It shows the patient understands that the device acts as a "miniature emergency department" that monitors for dysrhythmias and intervenes electrically to stop a "bad rhythm." This demonstrates the most fundamental understanding of the device’s life-saving function.