The correct answer is A. packet switching.
Packet switching is a method of digital networking in which data is broken up into small units called packets. These packets are then routed through a network independently of each other. This allows for more efficient use of network resources, as packets can be routed around congested areas.
Circuit switching is a method of digital networking in which a dedicated circuit is established between two points before any data is transmitted. This ensures that the data is transmitted without interruption. However, it is less efficient than packet switching, as the circuit is reserved for the entire duration of the transmission, even if there is no data being transmitted.
Telephone switching is a method of connecting telephone calls. It is a circuit-switched network, which means that a dedicated circuit is established between the caller and the callee for the duration of the call.
Telex switching is a method of connecting telex machines. It is a circuit-switched network, which means that a dedicated circuit is established between the two telex machines for the duration of the connection.
In conclusion, the Internet uses packet switching, which is a more efficient method of networking than circuit switching.