Which of the following is an example of a digital communications method?

Digital communication methods in amateur radio encompass a variety of protocols that utilize binary encoding to transmit information over radio frequencies. Each of the mentioned methods represents a distinct type of digital communication.

Packet is a technique that organizes data into packets, allowing for efficient error correction and ensures that transmitted information is received accurately. It is widely used for computer communications over radio frequencies.

PSK31 utilizes phase-shift keying to encode and modulate text into digital signals. This method is designed for efficient narrowband transmission, making it suitable for keyboard-to-keyboard communication.

MFSK, or Multiple Frequency Shift Keying, is another digital mode that transmits data by shifting between multiple frequencies. It is particularly effective for sending text and images in noisy environments due to its robustness against interference.

Given that all these methods are valid examples of digital communications, the correct answer encompasses them collectively. Its inclusion reflects the variety of digital communication practices available within amateur radio.