Which of the following terms best describes the ability to increase access to server resources and provide fail-safe services by linking two or more discrete computer systems, so they appear to function as though they are one?Group of answer choicesRoutingClusteringFailoverBack-up

The term that best describes the ability to increase access to server resources and provide fail-safe services by linking two or more discrete computer systems, so they appear to function as though they are one, is Clustering.

Here's why:

1. Routing: This is the process of selecting a path for traffic in a network or between or across multiple networks. It doesn't involve linking two or more discrete computer systems to function as one.

2. Clustering: This is the process of linking two or more computers together in such a way that they behave like a single computer. Clusters are typically used for High Availability for greater reliability or High Performance Computing to provide greater computational power.

3. Failover: This is a backup operational mode in which the functions of a system component (such as a processor, server, network, or database) are assumed by secondary system components when the primary component becomes unavailable through either failure or scheduled down time. It doesn't involve linking two or more discrete computer systems to function as one.

4. Back-up: This is the process of copying files or databases so that they will be preserved in case of equipment failure or other catastrophe. It doesn't involve linking two or more discrete computer systems to function as one.