Which type of switching is used by the public switched telephone network (PSTN) that creates a dedicated physical path?

The type of switching used by the public switched telephone network (PSTN) that creates a dedicated physical path is circuit switching. This method establishes a fixed communication path between the calling and receiving parties for the duration of a call. In circuit switching, a dedicated circuit is reserved for the entire conversation, which ensures that the necessary bandwidth is consistently available throughout the call.

This approach is particularly effective for traditional voice communication, where continuous and real-time transmission is critical. In contrast to packet switching, where data is divided into packets that travel separately and may take different routes, circuit switching guarantees a stable connection with predictable performance.

The other methods like digital switching incorporate aspects of circuit switching but also utilize packet-based techniques, while packet switching itself is not designed to create a dedicated path. Radio switching pertains to wireless transmission methods and does not apply to the fundamental operation of the PSTN. Thus, the correctness of this answer reflects an understanding of how circuit-switched networks function in ensuring a reliable and continuous communication channel.