Which of the following will exert a force on a magnet? another magnet a nearby piece of glass a nearby piece of plastic a nearby electric current

The nearby magnet and the electric current both will.

The magnet will attract or repell the other magnet so magnet is one answer

the glass obviously doesn't exert a force

the ellectric current makes the ellectrons and protons, in the current, allign so that they attract or repell the other magnet