1, 2 & 4 are going to be the the correct answer for the question
SI will always be in metric, so the answer is D. Meter.
Answer:
We understand that two like poles of magnet repel each other. Maglev train is based on the same concept. The train levitates above the tracks because of repulsion between one set of magnets. One set of magnets lifts the train upwards causing it to levitate or float above tracks and other set of magnets causes it to move forward. This method enables less consumption of energy as loss of energy due to friction is negligible and also, high speed can be achieved.
I think it would be the fourth one
