You work as an administrator at ABC.com. The ABC.com network consists of a single domain named ABC.com. All servers in the ABC.com domain， including domain controllers， have Windows Server 2012 R2 installed.The ABC.com network has a server named ABC_SR07 that hosts two virtual machines. You use Windows Server Backup to configure scheduled backups of ABC_SR07.  How would you ensure that all virtual machines will be saved before the backups begin？（）