单项选择题 Your company has a single Active Directory domain. The company network is protected by a firewall.Remote users connect to your network through a VPN server by using PPTP. When the users try to connect to the VPN server, they receive the following error message: °Error 721: The remote computer is not responding.You need to ensure that users can establish a VPN connection. What should you do？（）

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 7. You need to configure the client computers in the North 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 company has an Active Directory domain named ad.contoso.com. All client computers run Windows 7. The company has recently acquired a company that has an Active Directory domain named ad.fabrikam.com. A two-way forest trust is established between the ad.fabrikam.com domain and the ad.contoso.com domain. You need to edit the ad.contoso.com domain Group Policy object (GPO) to enable users in the ad.contoso.com domain to access resources in the ad.fabrikam.com domain. What should you do？（）