You have a DNS server named Server1 that runs Windows Server 2003 Service Pack 2 （SP2）. You have two Web servers named Server2 and Server3. The Web servers host an internal Web site that will be accessed by the URL http：//www.contoso.com. You need to ensure that requests for www.contoso.com are distributed between Server2 and Server3. What should you do？（）
- AOn each Web server， configure a host header value of www.contoso.com.
- BOn each Web server， configure a custom HTTP header value of www.contoso.com.
- COn Server1， create two host （A） records for www.contoso.com.
- DOn Server1， create a _roundrobin._tcp.contoso.com service locator （SRV） record for each server that has a port value of 80.