Your network contains a Web-based application that runs on Windows Server 2003. You plan to migrate the Web-based application to Windows Server 2008 R2. You need to recommend a server configuration to support the Web-based application. The server configuration must meet the following requirements： èEnsure that the application is available to all users if a single server？fails èSupport the installation of .NET applications èMinimize software costs What should you recommend？（）
- AInstall the Server Core installation of Windows Server 2008 R2 Standard on two servers. Configure the servers in a Network Load Balancing cluster.
- BInstall the full installation of Windows Server 2008 R2 Web on two servers. Configure the servers in a Network Load Balancing cluster.
- CInstall the full installation of Windows Server 2008 R2 Enterprise on two servers. Configure the servers in a failover cluster.
- DInstall the full installation of Windows Server 2008 R2 Datacenter on two servers. Configure the servers in a failover cluster.