单项选择题 Your company has a single active directory forest that has a domain in north America named na.contoso.com and a domain in south America named sa.contoso.com. the client computers run windows vista. You need to configure the client computes in the America office to improve the name resolution response time for resources in the south America office what should you do?（）

单项选择题 Your network contains a DNS server named DNS1 that runs Windows Server 2008 R2. DNS1 hosts a zone named contoso.com.Dynamic updates are enabled on the zone.The network contains a server named Web1.contoso.com.All computers on the network are configured to use DNS1 as their DNS server.You need to ensure that users can connect to Web1.contoso.com by using the name portal.contoso.com.The solution must ensure that the users can connect by using portal. contoso.com if the IP address of Web1.contoso.com changes.Which type of resource record should you create？（）

单项选择题 Your company has two servers that run windows server 2008 named server2 and server3, both servers have the DNS server role installed. Server3 is configured to forward all DNS requests to server2. You update a DNS record on server2, you need to ensure that server3 is able to immediately resolve the updated DNS record. What should you do?（）