Final answer:
A magnet is most likely to interfere with the function of an implanted cardiac pacemaker.It is important for individuals with pacemakers to avoid close contact with magnets, such as those found in magnetic closures, MRI machines, or strong refrigerator magnets.
Step-by-step explanation:
The most likely item to interfere with the function of an implanted cardiac pacemaker is a magnet.
Pacemakers can be affected by strong magnetic fields, which can disrupt their function.
It is important for individuals with pacemakers to avoid close contact with magnets, such as those found in magnetic closures, MRI machines, or strong refrigerator magnets.