Which of the following correctly orders dynamic markings from softest to loudest?

Responses

piano, mezzo-forte, mezzo-piano, forte
piano, mezzo-forte, mezzo-piano, forte - no response given

pianissimo, piano, fortissimo, forte
pianissimo, piano, fortissimo, forte - no response given

piano, mezzo-forte, forte, fortissimo
piano, mezzo-forte, forte, fortissimo - no response given

pianissimo, mezzo-piano, piano, forte

pianissimo, mezzo-piano, piano, forte

The correct order of dynamic markings from softest to loudest is: pianissimo, piano, mezzo-piano, forte.