问题：

[单选]

You are the network administrator for TestKing.com. The network consists of a single Active Directory domain named testking.com. The domain contains Windows Server 2003 computers and Windows XP Professional computers.
You use a non-administrative user account named Joseph to log on to a client computer. You need to change the password for a domain user account named Sophia.
You open the Active Directory Users and Computers console. When you attempt to change Sophia's password, you receive the following error message: "Access is denied".
You need to remain logged on to the client computer as Joseph, and you need to be able to change Sophia's password.
What should you do?（）

A . Add the non-administrative domain user account to the local Administrators group.
B . Use the runas command to run Active Directory Users and Computers with domain administrative credentials.
C . From a command prompt, run the net user Sophia /add /passwordreq:yes command.
D . From a command prompt, run the net accounts /uniquepw: /domain command.