Your network contains an Active Directory domain. The domain contains five domain controllers.   A domain controller named DC1 has the DHCP role and the file server role installed.   You need to move the Active Directory database on DC1 to an alternate location. The solution must  minimize impact on the network during the database move.   What should you do first（）

• A、Restart DC1 in Safe Mode.
• B、Restart DC1 in Directory Services Restore Mode.
• C、Start DC1 from Windows pe.
• D、Stop the Active Directory Domain Services service on dc1.