A mechanic dropped a bolt he needed to repair a car motor. He decided to make a simple electromagnet to try to attract the metal bolt. Which list of material would make the best electromagnet? A. metal rod for a core, copper wire, 9-volt battery B. glass rod for a core, copper wire, 9-volt battery C. plastic rod for a core, copper wire, 9-volt battery D. wooden rod for a core, copper wire, 9-volt battery
what is the correct option?