An administrator recommends using a tower server in a small remote office. Which of the following should be added to the server to ensure continuous server operation?

A surge protector protects against voltage spikes but does not provide continuous power during a power outage, nor does it regulate voltage sags.

A PDU (Power Distribution Unit) provides multiple outlets for power distribution within a rack or server setup and may offer basic surge protection or remote power control, but it does not supply backup power during an outage.

A UPS (Uninterruptible Power Supply) provides battery backup power to the server during power outages, allowing it to continue operating for a period or to shut down gracefully, preventing data corruption and ensuring continuous server operation. It also protects against power surges and sags.

A ground strap is used to prevent electrostatic discharge (ESD) when working on server components, protecting hardware during maintenance, but it does not ensure continuous server operation in the event of power issues.