Answer:D)Network segmentation
Step-by-step explanation: Network segmentation is the function of the networking system .It basically works by the division/splitting of the computer network into the sub-parts known as sub-networks/segments.This phenomena is followed for the improvement in the network performance and also increase the protection.
Other options are incorrect air gapped network is techniques for maintaining the security, load-balanced network is distributing traffic in a way to balance network and network address translation permits multiple device for accessing through individual address.Thus, the correct option is option(D). Network administrator should use network segmentation for communicating with back to server hub.