Final answer:
The link light on a switch or hub signifies the link status of a port, indicating a physical connection that is ready for data transmission.
Step-by-step explanation:
A link light on a switch or hub indicates the status of a network connection for a particular port. When the link light is on, it typically means that there is a physical connection and the port is ready for data transmission. The light can also show the quality of the connection (steady light usually means a good connection, while a blinking light can indicate that data is currently being transmitted).
In the context of the given options, the correct answer is (c) Link status. This signifies that a device is properly connected to the switch or hub, allowing for potential data transmission. However, it does not specifically indicate Internet connectivity, data transmission in progress, or the power status of the device or switch.