Which of the following is a digital communications mode?

Digital communications modes allow for the transmission of information using digital signals, providing various techniques to send and receive data effectively. Packet radio is a form of digital communication that uses packets of information for transmission, making it suitable for networks and allowing multiple users to share the same frequency. IEEE 802.11 refers primarily to a set of standards for wireless networking, often associated with Wi-Fi technology, which fundamentally relies on digital communication methods to connect devices over radio waves.

FT8 is a specific digital mode used in weak signal communications, particularly in amateur radio, which uses a structured protocol to send and receive messages efficiently, even under conditions of low signal strength. Each of these choices represents a valid form of digital communication, showcasing different applications and technologies within this realm.

Since all options are recognized as digital communication modes, the correct answer encompasses the idea that multiple formats of digital communication exist, making the answer comprehensive and inclusive of all provided choices.