You have a domain controller named Server1 that runs Windows Server 2008 R2.     You need to determine the size of the Active Directory database on Server1.     What should you do（）

• A、Run the Active Directory Sizer tool.
• B、Run the Active Directory Diagnostics data collector set.
• C、From Windows Explorer， view the properties of the %systemroot%/ntds/ntds.dit file.
• D、From Windows Explorer， view the properties of the %systemroot%/sysvol/domain folder.