Which device does a Local Area Network (LAN) need to communicate over the Internet?

A Local Area Network (LAN) requires a router to communicate over the Internet.

The router serves as a gateway that connects the LAN to the external network (Internet) and directs data traffic between the LAN and the Internet.

The other options:

Multiplexer combines multiple signals into one.

Repeater amplifies signals to extend the range.

Switch connects devices within the LAN but does not facilitate Internet communication.

Therefore, a router is the necessary device for a LAN to communicate over the Internet.