How can electromagnetic induction be best defined?

Electromagnetic induction refers to the process by which a changing magnetic field within a coil of wire induces an electromotive force (EMF) in the conductor. This phenomenon occurs particularly when a conductor, such as a wire, moves through a magnetic field, effectively "cutting" across the lines of magnetic flux. This interaction allows for the generation of electricity from the kinetic energy of the movement, a fundamental principle behind many electrical devices, including generators and transformers.

The essence of option B highlights the critical role of movement in the induction process, where the conductor's interaction with the magnetic field leads to the generation of electric current. Understanding this principle is key to grasping how many modern electrical systems operate, emphasizing the link between motion and the production of electrical energy.