What role does a multiplexer serve in telecommunications?

A multiplexer is a crucial component in telecommunications that combines multiple signals into one for transmission over a single medium. This process is known as multiplexing. By consolidating various data streams into one signal, it allows for efficient use of bandwidth and reduces the need for multiple transmission paths.

When different signals are merged, the multiplexer ensures that the information from each source is preserved and can be distinguished at the receiving end, allowing for multiple data channels to be sent over a single communication line without interference. This is especially beneficial in reducing costs and optimizing the use of network resources.

The other options address different functions or components within telecommunications. For instance, encryption of signals is handled by different systems designed for security, while amplifying or splitting signals is achieved by amplifiers and splitters, which focus on other aspects of signal management rather than combining them for streamlined transmission.