Explanation
Bonding multiple 20MHz wide 802.11 channels is a technique to create a wider bandwidth channel that supports higher data rate transmissions. It can increase the throughput between the client and AP by using more spectrum resources and reducing interference. References:https://ieeexplore.ieee.org/document/9288995

WPA3-Personal enhances the security of wireless networks by using Simultaneous Authentication of Equals (SAE), which is a more secure replacement for the Pre-Shared Key (PSK) method used in WPA2. SAE strengthens the initial key exchange, providing better protection against offline dictionary attacks and ensuring that each session has a unique Pairwise Master Key (PMK), derived from the interaction between the client and the access point, including session-specific information like MAC addresses and nonces.

The ideal Aruba access switch for a cost-effective connection to 200-380 clients, printers and APs per distribution rack is the Aruba CX 6200. This switch series is a cloud-manageable, stackable access switch series that is ideal for enterprise branch offices and campus networks, as well as SMBs.
The CX 6200 series offers the following benefits:
- Enterprise-class connectivity: The CX 6200 series supports ACLs, robust QoS, and common protocols such as static and Access OSPF routing.
- Power and speed for users and IoT: The CX 6200 series provides built-in 1/10GbE uplinks and 30W to
60W of Class 4 to Class 6 PoE for powering devices such as APs and cameras.
- Scalable growth made simple: The CX 6200 series supports Aruba Virtual Switching Framework (VSF) that allows you to quickly grow your network to eight members in a single stack using high-performance built-in 10G SFP ports.
- Management flexibility: The CX 6200 series supports a choice of management, including cloud-based and on-prem Central, CLI, switch Web GUI and programmability with AOS-CX operating system, and REST APIs.
The other options are not ideal because:
- Aruba CX 6400: This switch series is a high-availability modular switch series that is ideal for versatile edge access to data center deployments. It offers more performance, scalability, and modularity than the CX 6200 series, but it is also more expensive and complex to deploy and manage. It may not be cost- effective for connecting 200-380 clients per distribution rack.
- Aruba CX 6300: This switch series is a layer 3 stackable access and aggregation switch series that offers Smart Rate and High Power PoE. It offers more features and performance than the CX 6200 series, but it is also more expensive and may not be necessary for connecting 200-380 clients per distribution rack.
- Aruba CX 6000: This switch series is a layer 2 access switch series that offers PoE. It offers less features and performance than the CX 6200 series, and it does not support VSF stacking or routing protocols. It may not be sufficient for connecting 200-380 clients per distribution rack.
References:
https://www.arubanetworks.com/products/switches/access/
https://www.arubanetworks.com/products/switches/access/6200-series/
https://www.arubanetworks.com/products/switches/access/6400-series/
https://www.arubanetworks.com/products/switches/access/6300-series/
https://www.arubanetworks.com/products/switches/access/6000-series/

The signal to noise ratio (SNR) is a measure that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels (dB). A high SNR means that the signal is clear and easy to detect or interpret, while a low SNR means that the signal is corrupted or obscured by noise and may be difficult to distinguish or recover3. To calculate the SNR in dB, we can use the following formula:
SNR (dB) = Signal power (dBm) - Noise power (dBm)
In this question, we are given that the noise floor measures -90 dBm (0.000000001 milliwatts) and the receiver's signal strength is -65 dBm (0.000316 milliwatts). Therefore, we can plug these values into the formula and get:
SNR (dB) = -65 dBm - (-90 dBm) SNR (dB) = -65 dBm + 90 dBm SNR (dB) = 25 dBm Therefore, the correct answer is that the SNR is 25 dBm.
References: 3 https://en.wikipedia.org/wiki/Signal-to-noise_ratio