A technician would like to setup load balancing on a file server. Which of the following additional devices will need to be added to the server?

Load balancing distributes incoming network traffic across multiple servers or network paths to optimize resource utilization and prevent overload. An additional Network Interface Card (NIC) can be added to a server to provide an extra network path for traffic distribution, especially in scenarios like network teaming or when a dedicated interface is needed for a load balancer.

A PBX (Private Branch Exchange) is a telephone system for managing internal and external calls, completely unrelated to network load balancing on a file server.

While a CPU is essential for server operation, adding another CPU would increase processing power, not directly facilitate network load balancing functionality, which is primarily a network function.

A USB (Universal Serial Bus) port is used for connecting peripherals like storage drives or input devices, and does not provide network connectivity for load balancing.