which storyline should I use?

I have four or five I would like to use... I'll give you a brief of each and please tell me which one strikes you as most interesting!

1) There's a border around all of what's left of united states and Canada. There's a girl, who lives at the edge of the border. Her family is rich, but she feels something missing. One day a very strong earthquake shatters some of the border near her house, and she sees a meadow, one that matches one she saw in a dream. She decides to go after it...

2) A boy is plugged in to all technology, and hears in the news everyday about more technology, i.e a woman getting the first ever cell-phone implant, and the new high-tech pace-maker, which lot's of people are going to need, because tecchnology causes the next generatin to have a lot more defects. Then suddenly an EMP takes out a lot of the technology in the NA continent, and over half of the population dies immediately from either suicide, or not having life saving tech in their bodies/at hospitals. The boy goes on to find a pair of twins, who didn't die, but their parents did. The three of them wander off in search of other life.... while surviving without technology

3) An ice age is approching, and many glaciers have popped up everywhere, one avalanche takes out a whole state/province. A few provinces/states over, is a camp where lots of kids have families in the devastated area. Their are being taken back by bus, when the bus crashes and all but three people die....

4) People live underground, becasue Nuclear radiation prevents them from even breathing fresh air. A disease starts taking lives, and takes a girls father, and threatens to take her younger brother if he doesn't recive a vaccine. She steals the vaccine, but it's the very last one. And the "president" has caught the disease too. she has to go above ground and retrive the vital ingriedient beefore he dies, or else they all die...