You are the enterprise administrator for a company named Contoso, Ltd.
The network consists of one Active Directory domain named contoso.com.
You have a Microsoft Exchange Server 2007 organization named Contoso.
All users log on to their computers by using credentials identical to their e-mail addresses.
The company plans to change its name to Adatum Corporation and modify all user e-mail addresses to include a new adatum.com domain name.
You need to enable all users to log on to their computers by using the new domain name. The solution must not disrupt existing applications on the network.
What should you do first?
A.
Use the Active Directory domain Rename Tool to rename the domain to adatum.com.
B.
Use the DNS Management Console to create a new forward lookup zone named adatum.com.
C.
Create an alternative user principal name (UPN) suffix of adatum.com.
D.
Create a new accepted domain named adatum.com in the Exchange Server 2007 organization.