When designing a WLAN for applications like Telnet, which are sensitive to latency and require consistent connectivity, it's crucial to minimize co-channel interference.Reducing the AP transmit power helps in creating smaller cells, thereby limiting the overlap between adjacent APs operating on the same channel.This approach reduces contention and interference, ensuring a more stable and reliable connection for latency- sensitive applications.
Reference: CWDP-305 Official Study and Reference Guide, Chapter on Designing for Specific Applications

The maximum theoretical signal gain of chip-based TxBF and MRC depends on the number of antennas and the channel conditions. TxBF (transmit beamforming) is a technique that focuses the transmitted signal in the direction of the intended receiver, resulting in higher signal strength and less interference. MRC (maximum ratio combining) is a technique that combines the signals received by multiple antennas in an optimal way, resulting in higher signal-to-noise ratio and better performance. The theoretical gain of TxBF and MRC can be calculated as GTxBF=10log10(N) and GMRC=10log10(N) where N is the number of antennas. Therefore, the total gain of TxBF and MRC is Gtotal=GTxBF+GMRC=20log10(N) However, this is the ideal case and assumes perfect channel conditions and alignment. In reality, the gain is lower due to factors such as channel fading, antenna spacing, and feedback delay. According to the CWDP study guide1, the typical gain of TxBF and MRC is about 4-6.5 dBi for 2 antennas, 7-10 dBi for 3 antennas, and 10-13 dBi for 4 antennas. Therefore, the answer is D. Reference: 1: CWDP Certified Wireless Design Professional Official Study Guide: Exam PW0-250, Chapter 8, page 267.