A technician is plugging an Ethernet cable into a switch to bring a new device...

The correct answer is D. Administratively down. The question states that another technician had already turned off unused switchports as part of hardening. When a port is intentionally disabled by configuration, its status is described as administratively down. In other words, the switchport is not broken and has not failed on its own; it has simply been shut down by an administrator.

This is a common security practice. Unused ports are often disabled so unauthorized devices cannot be plugged in and gain access to the network. If a legitimate device later needs that port, the administrator must re-enable it before the link can come up.

The other answer choices do not line up as well with the scenario. Error disabled usually points to a protective shutdown caused by a violation or fault, such as port security or BPDU guard. Idle is not the standard description for a manually shut switchport in this context. Suspended can appear with certain switch features, but it is not the normal label for a port deliberately turned off as part of hardening.

The phrase “turned off unused switchports” is the key detail. That clearly indicates a manual administrative shutdown, so administratively down is the best answer.