Network Address Translation (NAT) is the correct answer because it allows multiple devices on a private network to access the internet using a single public IP address. It masks the private IP addresses of internal hosts, making them invisible to the outside world and providing an extra layer of security against external threats. A VPN would not hide private addresses from the external network; instead, it would create a secure connection to another network. Dynamic Host Configuration Protocol (DHCP) is used for dynamically assigning IP addresses to network devices but doesn't provide the required address translation.