Used car lots and metal scrapyards use electromagnets to move pieces of metal from one place to another. If the electromagnet/crane operator

Used car lots and metal scrapyards use electromagnets to move pieces of metal from one place to another. If the electromagnet/crane operator needed to drop a car to a new space, what would he need to do for this to happen? A) Lift the electromagnet farther away from the pile of cars. B) Reverse the magnetic field by switching the poles of the core. C) Turn off the magnetic field by switching off the electric current. The magnetic field can be decreased by placing it close to another electromagnet​