Answer: C: Repairing or recovering active directory in directory services restore mode (DSRM)
Explanation:
Directory Services Restore Mode (DSRM) is operated in a safe mode using safe mode administrator password to recover or repair Active Directory of database.
DSRM password is selected during installation of Active Directory, providing database access to administrator in case of loss. Password can be changed through NTDSUtil In case admin forget password.