Reg best approach of Backup Restore in SharepointOnline

Hi 

Among the below mentioned ways which will be the best approach to backup and restore sharepoint online site data. Also which approach is effective but cheaper tool to retain the backup for maximum days.Kindly suggest.

1.    Using the Recycle bins and version control<o:p></o:p>

2.    Third party tools that can back up your Data<o:p></o:p>

3.    Make a service request in your portal<o:p></o:p>

4.    Make a manual backup of your Sites or Document library

Ki

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Janani.R