Does the wording of the competition say 'contemporary'? If so, none of those pieces will do because they're not contemporary. There's not one absolute definition of the word 'contemporary' but it's best to pick a piece by a living composer if they ask for a contemporary piece. If they ask for a 20th-century piece then all of those will be fine, but personally I think it's good to play something by a living composer anyway, because classical music is a valuable living tradition to be continued.I couldn't possibly choose between Ravel and Prokofiev concertos because they're both wonderful and fantastic and I hope one day to be able to play at one of them. Best of luck!