A Virtual Private Network (VPN) is a "tunnel" connection between computers that performs just like a regular point-to-point network connection (that is, IP address to IP address). It has the added feature that encryption is enabled so that no intermediate server (or computer or line monitor, etc.) can decode the information that is in the data portion of the packets.
Answers A, C, and D are simply not true. This makes the choice pretty easy. For (A), the VPN connections transfers all data just like a regular connection would; for (C) if your boss only needs his remote computer, why is he connecting to the company network?; and for (D) NTFS is the file system used by Windows PCs, but VPNs may connect UNIX/Linux machines, Apples, and even embedded computers (like inside a home security system or an automobile engine).