Magnetic Battery
This is a device which converts magnetic field energy into electrical energy so in this part we got the electric energy out of it
Coil Magnet
This type of magnet is always in shape of coil which will produce the magnetic field along the axis.
Coil circuit
This is just type of the circuit which will produce the current in closed loop.
Electromagnet
In electromagnets we got the magnetic field energy which is converted by electric energy i.e. in this form we have to supply the current in the circuit and then it will produce the magnetic field of that current
So correct answer is electromagnet
