The correct response is:
Magnets in front of the train constantly pull magnets in the train toward them.
In a maglev train system, magnetic forces are used both for levitation (to lift the train off the track) and propulsion (to move the train forward). The magnets in front of the train create a magnetic field that pulls the train forward, while those in the back help to push it along. This allows the train to move smoothly and at high speeds without touching the track.