A VPN (Virtual Private Network) creates a secure, encrypted connection over the internet between the user and a remote network, enabling secure access from home or public networks.

''VPNs provide a secure tunnel for transmitting data over unsecured networks, such as the internet, by encrypting all traffic between the client and the network.'' --- CompTIA ITF+ Security Topics

Other options:

A . LAN -- Local and not for remote use

B . FTP -- Transfers files but lacks modern encryption

C . DNS -- Resolves domain names, not for access

Correct answer: D