IEEE 802.11ax, also known as Wi-Fi 6, introduces several advancements to improve network performance, particularly in dense environments. Among these,OFDMA (Orthogonal Frequency Division Multiple Access)is a key feature introduced by 802.11ax. OFDMA allows more efficient use of the available spectrum by enabling multiple users to share the same channel simultaneously. This is done by subdividing the channel into smaller sub-channels, allowing data to be transmitted to multiple devices at the same time, improving overall throughput and reducing latency.

Option A: 60 GHz utilizationrefers to Wi-Fi standards like 802.11ad and 802.11ay, which use the 60 GHz band, but 802.11ax focuses on improving efficiency in the 2.4 GHz and 5 GHz bands, not the 60 GHz band.

Option B: Wi-Fi multimediais related to Wi-Fi features that prioritize multimedia traffic, but it is not a new attribute specifically introduced by 802.11ax.

Option D: MIMO (Multiple Input, Multiple Output)is a technology that allows multiple antennas to be used at both the transmitter and receiver, and while MIMO is supported in 802.11ac, it was enhanced in 802.11ax withMU-MIMO (Multi-User MIMO)for uplink, not a new technology introduced by 802.11ax.

Therefore,OFDMA(Option C) is the correct answer, as it is a key feature that 802.11ax introduces to improve network efficiency and capacity.