Which item is necessary to make an electromagnet?

An electromagnet is a device which has conducting wires wrapped around an iron core. When, electricity is passed through the wires, a magnetic field is generated. The set up acts as a strong magnet.

For making an electromagnet, a current carrying wire wrapped around a magnetic material is required. So out of the given pictures, the conducting wires are necessary to make an electromagnet. The correct option is the last picture.

i'm thinking more like energy

i think its c if i'm wrong