Please choose the correct ending to complete the given sentence: Computers and Electronics: [header] How to rejuvenate your smartphone [title] Back it up. [step] Want to add more apps and games into your phone but don't have enough dollars to get an sd card? All you have to do is back up all the data in your phone to an external device or the cloud so that you can enjoy the smartphone experience like it's new. [title] Clear the cache.

Ending1: [step] Many of the websites and apps create cache files in your phone so they can access it faster next time you open them up. But doing this will only take memory from your device. Ending2: [step] It is possible that you're connected to an via network or shared network and so it is unusable. Clear your entire system by plugging your phone in a power outlet and have everything powered off. Ending3: [step] This can be done by pressing the back button so that the cache pops up. [title] Open zune's heat protection program. Ending4: [step] Files that are impossible to access are right on the cache. But remember, you aren't conning it, but trying to keep access from possible thieves.

Answer format: ending1/ending2/ending3/ending4