Which three elements determine Air Time efficiency? (Choose three)

Event-driven RRM (Radio Resource Management) is a mechanism to adapt RF parameters, which can *improve* efficiency, but it is not a fundamental *element* that *determines* the intrinsic airtime efficiency itself.

Data rate, which is directly influenced by modulation and coding schemes (e.g., QAM), determines how many bits can be carried per symbol, thus impacting how much data can be transmitted in a given unit of time.

Wider channel bandwidths (e.g., 40 MHz, 80 MHz, 160 MHz) allow for a larger amount of data to be transmitted concurrently, directly increasing the overall throughput and efficient use of airtime.

The number of spatial streams (MIMO) enables parallel data transmission over the same frequency, while spatial reuse techniques (e.g., OFDMA, BSS coloring) allow for more efficient utilization of frequency resources across multiple clients or access points, both critically enhancing airtime efficiency.

An RF group leader is a functional role in a Cisco RRM deployment responsible for managing RF parameters for a group of APs, but it does not directly determine airtime efficiency.

Dynamic Channel Assignment (DCA) is an RRM feature that aims to reduce interference by assigning optimal channels, thereby *improving* efficiency, but it is a management function rather than a direct element that determines how much data can be carried over the air.