Explain how gravitational, electrical, and magnetic force act on a maglev train?

 After a little bit of research:

Electrical energy keeps the plane moving while Gravitational force from the Earth is pulling the train downward( do to it's heavy mass and density, it has much greater gravitational pull then us humans experience). Magnetic transfusions has an equal force upwards to keep the load balanced.( think of it as how a roller coaster works).

i think the answer would d

if your own plato the answer is b. the fern transitioned from sporophyte generation to gametophyte generation.