Digital modulation is accomplished by shifting the _____________ of the carrier wave.

Digital modulation involves altering specific characteristics of a carrier wave to encode information for transmission. When focusing on the correct choice, shifting the phase of the carrier wave is a fundamental technique utilized in several digital modulation schemes, such as Phase Shift Keying (PSK). In PSK, the phase of the carrier signal is changed according to the digital data being transmitted, allowing for effective representation of binary or multi-level signals.

Changing the phase means that the time relationship of the signal with respect to a reference is altered, which corresponds to the transmission of different symbols or bits. This method allows for relatively efficient use of bandwidth while maintaining good performance in various noise conditions.

Other options, like amplitude, frequency, and wavelength, are also important in different modulation techniques, such as Amplitude Shift Keying (ASK) and Frequency Shift Keying (FSK), but they do not specifically describe the hallmark of digital modulation in the context of phase-based methods. Therefore, phase modulation stands out as the key aspect in defining how digital data is represented in the carrier wave for digital communications.