our network consists of a single Active Directory domain. You have a DHCP server that runs Windows Server 2003 Service Pack 2 (SP2). All client computers run Windows XP Service Pack 3 (SP3). A user named User1 reports that when she starts her computer, she receives a duplicate address error message. You confirm that her computer is configured as a DHCP client. You need to ensure that User1 receives a unique IP address from the DHCP server. What should you do on the DHCP server? （）

A. Reconcile the scope.
B. Create a superscope.
C. Enable conflict resolution.
D. Increase the number of IP addresses available in the scope.