You have four DCs in your domain. Active Directory appears to be corrupted on one of the DCs, and you suspect a failing hard drive. You attempt to remove it from the domain, but the procedure fails. You take the DC offline permanently and will replace it with another DC of the same name. What must you do before you can replace the DC?
a. Restore the system state.
b. Perform metadata cleanup.
c. Back up SYSVOL.
d. Transfer the FSMO roles.