Which modulation, which was introduced in 802.11ac standard, influences end-user experience by providing the highest data rates and throughput?

256 QAM (Quadrature Amplitude Modulation) is the highest-order modulation supported by 802.11ac. It encodes 8 bits per symbol, allowing for the transmission of significantly more data in the same amount of time compared to lower-order QAM schemes, thereby maximizing data rates and throughput.

QPSK (Quadrature Phase Shift Keying) encodes only 2 bits per symbol, offering much lower data rates than 256 QAM and is typically used in less ideal signal conditions.

16 QAM (16-state Quadrature Amplitude Modulation) encodes 4 bits per symbol, providing lower data rates compared to 256 QAM.

64 QAM (64-state Quadrature Amplitude Modulation) encodes 6 bits per symbol, which results in lower data rates compared to 256 QAM.