The method of slicing digital messages into parcels, transmitting them along different communication paths, and reassembling them at their destinations is called?

The correct choice is packet switching, which refers to the method of breaking down digital messages into smaller, manageable units called packets. Each of these packets can then be transmitted independently over various network routes. Once all packets reach their destination, they are reassembled in the correct order to reconstruct the original message. This technique is fundamental to how data is transmitted over the internet, allowing for efficient and reliable communication even if some packets take different paths due to varying network conditions.

Packet switching optimizes bandwidth usage and can improve overall transmission speed because it does not require a dedicated path for the entire message. Instead, it utilizes available resources dynamically, which is crucial for modern networks that support numerous simultaneous communications.

The other terms relate to different but important networking concepts. Multiplexing refers to combining multiple signals into one transmission medium but does not involve breaking messages into packets. Packet routing describes the process of directing packets through the network but does not encompass the entire process of slicing and reassembling messages. ATM (Asynchronous Transfer Mode) is a networking technology that uses fixed-size packets called cells, however, it is a specific implementation rather than a general method like packet switching.