The technician is installing a new video card. Which of the following actions should the technician perform prior to installation?

Disconnecting only the power supply from the motherboard still leaves other components energized and does not fully de-energize the system before internal work.

Disconnecting the UPS from the wall outlet is unrelated to the internal installation task and does not directly remove power from the workstation being serviced.

A PoE cable supplies network power to network devices such as IP phones or access points and has no relevance to installing a video card in a workstation.

Disconnecting power from the workstation's power supply (turning off and unplugging the PC) removes all electrical current from the system. This is the standard ESD and electrical safety procedure required before handling internal components like a video card, ensuring no live voltage is present on the motherboard or expansion slots.