Correct Answer: D
Explanation/Reference:
Remote Desktop Gateway (RD Gateway) is a role service that enables authorized remote users to connect to resources on an internal corporate or private network, from any Internet-connected device that can run the Remote Desktop Connection (RDC) client. The network resources can be Remote Desktop Session Host (RD Session Host) servers, RD Session Host servers running RemoteApp programs, or computers with Remote Desktop enabled.
RD Gateway uses the Remote Desktop Protocol (RDP) over HTTPS to establish a secure, encrypted connection between remote users on the Internet and the internal network resources on which their productivity applications run.
DirectAccess, introduced in the Windows 7 and Windows Server 2008 R2 operating systems, allows remote users to securely access enterprise shares, web sites, and applications without connecting to a virtual private network (VPN).