The difference in the noise floor perceived by a client using a bonded 40 MHz wide channel as compared to an unbonded 20 MHz wide channel is 3 dB. The noise floor is the level of background noise in a given frequency band. When two adjacent channels are bonded, the noise floor increases by 3 dB because the bandwidth is doubled and more noise is captured. The other options are incorrect because they do not reflect the correct relationship between bandwidth and noise floor.

Strict queuing is the best scheduling technology to use for voice traffic on an AOS-CX switch. Scheduling is a mechanism that determines how packets are transmitted from different queues on an egress port. Strict queuing is a scheduling method that gives the highest priority queue absolute preference over all other queues, regardless of their size or utilization. Voice traffic should be assigned to the highest priority queue and scheduled with strict queuing to ensure minimal latency and jitter. The other options are incorrect because they are either not scheduling methods or not optimal for voice traffic. References:
https://www.arubanetworks.com/techdocs/AOS-CX/10.04/HTML/5200-6728/bk01-ch02.htmlhttps://www.aruba

The correct answer is B. Spanning-tree instance VLAN mapping.
To load-balance VLANs with MSTP, you need to configure the same VLAN-to-instance mapping on all switches in the same MST region. This means that you need to assign different VLANs to different MST instances, and then adjust the spanning tree parameters (such as priority, cost, or port role) for each instance to achieve the desired load balancing. For example, you can make one switch the root for instance 1 and another switch the root for instance 2, and then map half of the VLANs to instance 1 and the other half to instance 2.
According to the Cisco document Understand the Multiple Spanning Tree Protocol (802.1s), one of the steps to configure MST is:
Split your set of VLANs into more instances and configure different MST settings for each of these instances. In order to easily achieve this, elect Bridge D1 to be the root for VLANs 501 through 1000, and Bridge D2 to be the root for VLANs 1 through 500.
These statements are true for this configuration:
Switch D1(config)#spanning-tree mst configuration
Switch D1(config-mst)#instance 1 vlan 501-1000
Switch D1(config-mst)#exit
Switch D1(config)#spanning-tree mst 1 priority 0
Switch D2(config)#spanning-tree mst configuration
Switch D2(config-mst)#instance 2 vlan 1-500
Switch D2(config-mst)#exit
Switch D2(config)#spanning-tree mst 2 priority 0
The above commands create two MST instances, 1 and 2, and map VLANs 501-1000 to instance 1 and VLANs 1-500 to instance 2. Then, they make switch D1 the root for instance 1 and switch D2 the root for instance 2.
The other options are incorrect because:
A) Spanning-tree bpdu-guard setting is a security feature that disables a port if it receives a BPDU from an unauthorized device. It does not affect load balancing with MSTP.
C) Spanning-tree CIST mapping is not a valid command. CIST stands for Common and Internal Spanning Tree, which is the spanning tree instance that runs within an MST region and interacts with other regions or non-MST switches.
D) Spanning-tree root-guard setting is another security feature that prevents a port from becoming a root port if it receives superior BPDUs from another switch. It does not affect load balancing with MSTP.

Explanation
This is the correct action to fix the issue where the SSID is not working as expected. WPA3-Enhanced Open is a new security standard for public networks that uses Opportunistic Wireless Encryption (OWE) to provide encryption and privacy on open, non-password-protected networks. WPA3-Enhanced Open can be configured on an Aruba Access Point by changing the SSID security mode to WPA3-Enhanced Open in Aruba Central or Aruba Instant. The other options are incorrect because they either do not use WPA3-Enhanced Open or do not exist as valid security modes. References:
https://www.arubanetworks.com/assets/wp/WP_WPA3-Enhanced-Open.pdf
https://www.arubanetworks.com/techdocs/Instant_86_WebHelp/Content/instant-ug/wpa3-enhanced-open.htm

Two parts of the solution for these requirements are Option C and Option E.
Option C is a part of the solution because it defines a policy-based routing action list named route_test, which specifies the next hop IP address as 10.1.1.253 for the matching traffic. This is the new default route that the user wants to use for the subnet 10.2.250.0/24. The interface null parameter indicates that the traffic will be routed to the next hop without using a specific interface1.
Option E is a part of the solution because it applies the policy-based routing action list route_test to the VLAN interface 250, which has an IP address of 10.2.250.1/24. This is the subnet that the user wants to test the new default route for. The apply policy command enables policy-based routing on the interface and associates it with the action list2.
Option A is not a part of the solution because it defines a policy-based routing action list named route_test, but does not specify the next hop IP address as 10.1.1.253, which is the new default route that the user wants to use. Instead, it specifies a next hop IP address of 10.1.1.254, which is different from the requirement.
Option B is not a part of the solution because it defines a policy-based routing action list named route_test, but does not specify any next hop IP address at all, which is necessary for policy-based routing to work. Instead, it specifies an interface null parameter without any IP address, which is invalid.
Option D is not a part of the solution because it applies the policy-based routing action list route_test to the VLAN interface 200, which has an IP address of 10.2.200.1/24. This is not the subnet that the user wants to test the new default route for, but a different subnet that should not be affected by this change.