What should you do?

You work as the network administrator at Domain.com. The Domain.com network consists of a single Active Directory domain named Domain.com. Domain.com has its headquarters located in London and branch office located in Paris. All servers on the Domain.com network run Windows Server 2008 and all client computers run Windows Vista.
During the course of the day you receive instruction from Domain.com to log on to a client computer that has been offline for a year. You later started the computer and attempted to log on as the administrator and receive an error message stating that authentication failed. Domain.com wants you to ensure that you are able to log on and use the computer.
What should you do?

A.
You should consider having the netsh command run at the command prompt on the computer.

B.
You should consider having the netsh trust/reset command run at the command prompt.

C.
You should consider having the computer disjoined from the domain.

D.
You should consider having the computer account deleted from the organizational unit.

Explanation:
You should then have the machine options set.
You should then join the computer to the domain again.
You should then rejoin the computer to the domain and reset the computer account.
You should then have the account added to the organizational unit.

In the scenario you should have the computer disjoined from the domain and rejoined to the domain whilst having the computer account reset as well. You should additionally note that the long inactivity caused the computer to stop responding to the authentication query using the Active Directory records. You should note by disjoining and rejoining with the account being reset would refresh the computer account passwords.