What are the lights on a network adapter?

One of your customers is not able to browse the Internet from their workstation. When you look at the network adapter, you see that a light is on next to the RJ-45 connector. What does the light indicate?

A) The TCP/IP configuration on the user’s system is properly configured.

B) The adapter is physically connected to the network device on the other end of the RJ-45 cable.

C) The adapter cannot currently send network traffic across the network connection.

D) The connection to the Internet is operating normally.