What type of modulation involves modifying the wave height of a carrier wave?

The process of modifying the wave height of a carrier wave is known as Amplitude Modulation (AM). In AM, the amplitude, or height, of the carrier wave is varied in proportion to the waveform being sent, which encodes the information onto the wave for transmission. This means that the strength of the signal changes with the audio or data input, allowing for effective communication over radio frequencies.

In contrast, Pulse Modulation involves using pulses to convey information, where the modifications are related to the timing and width of these pulses rather than changes in amplitude. Frequency Modulation changes the frequency of the carrier wave instead of its amplitude, coding information by altering how quickly the wave oscillates. Phase Modulation focuses on varying the phase of the carrier wave to transmit data, without affecting the amplitude directly. These distinctions clarify why Amplitude Modulation is the correct answer for this question.