When a firewall takes an incoming request for a specific IP address and redirects it to an internal host, which of the following is being used?

NIS (Network Information Service) is a client-server directory service protocol used for distributed configuration data, not for redirecting network traffic.

PAT (Port Address Translation) is a specific form of NAT that maps multiple private IP addresses to a single public IP address using different port numbers, but the overarching technology for redirecting an incoming request to an internal host via address remapping is NAT.

Network Address Translation (NAT) is a method of remapping one IP address space into another by modifying network address information in the IP header of packets while they are in transit. When a firewall redirects an incoming request from an external IP to an internal host, it performs a destination NAT, translating the public IP and port to a private IP and port.

NIC (Network Interface Card) is a hardware component that connects a computer to a computer network, not a technology for redirecting network traffic.