A thin diamagnetic rod is placed vertically between the poles of an electromagnet. When,the current in the electromagnetis switched on, then the diamagnetic rod is pushed up, out,of the horizontal magnetic field. Hence, the rod gains gravitational potential energy. The work required to do this comes from

A

the induced electric field due to the changing magnetic field

B

the lattice structurejof the material of the rod

C

the magnetic field

D

the current source