What does PoE enable a switch to do?

Power over Ethernet (PoE) is a technology that allows network cables to carry electrical power along with data to powered devices, such as IP cameras, VoIP phones, and wireless access points. When a switch supports PoE, it can transmit both data and power through the same Ethernet cable, eliminating the need for separate power supplies for each device. This capability simplifies installation and reduces the amount of cabling required in a network setup.

The other options related to managing VLAN traffic, supporting Quality of Service (QoS) for video, or controlling access to the network refer to different functionalities that switches might perform but are not directly associated with the core functionality of PoE. While switches can indeed manage VLANs, implement QoS, and control network access, these capabilities do not pertain to the power delivery aspect that PoE provides. Hence, option A accurately captures the essence of what PoE enables a switch to do.