单项选择题 A domain controller named DC12 runs critical services. Restructuring of the organizational unit  hierarchy for the domain has been completed and unnecessary objects have been deleted.     You need to perform an offline defragmentation of the Active Directory database on DC12.  You  also need to ensure that the critical services remain online.     What should you do（）

单项选择题 You network consists of a single Active Directory domain. All domain controllers run Windows  Server 2008 R2.     You need to reset the Directory Services Restore Mode （DSRM） password on a domain  controller.     What tool should you use（）

单项选择题 Your company has a domain controller server that runs the Windows Server 2008 R2 operating  system. The server is a backup server. The server has a single 500-GB hard disk that has three  partitions for the operating system， applications， and data. You perform daily backups of the  server.     The hard disk fails. You replace the hard disk with a new hard disk of the same capacity. You  restart the computer on the installation media. You select the Repair your computer option.     You need to restore the operating system and all files.     What should you do（）