CoS and DSCP are both methods of marking packets for quality of service (QoS) purposes. QoS is a mechanism that allows network devices to prioritize and differentiate traffic based on certain criteria, such as application type, source, destination, etc. CoS stands for Class of Service and is a 3-bit field in the 802.1Q VLAN tag header. CoS can only be used on Ethernet frames that have a VLAN tag, and it can only be preserved within a single VLAN domain. DSCP stands for Differentiated Services Code Point and is a 6-bit field in the IP header. DSCP can be used on any IP packet, regardless of the underlying layer 2 technology, and it can be preserved throughout the IP packet flow, unless it is modified by intermediate devices.
References: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos/configuration/15-mt/qos-15-mt-book/qos-overview.html https://www.cisco.com/c/en/us/support/docs/lan-switching/8021q/17056-741-4.html
https://www.cisco.com/c/en/us/support/docs/quality-of-service-qos/qos-packet-marking/10103-dscpvalues.html

https://www.arubanetworks.com/techdocs/AOS-CX/10.07/HTML/5200-7885/Content/Chp_Mng_Use/bui-in- use-gro-the-pri-10.htm

This is the correct statement about what happens when a client attempts to join the network and the WLAN is configured with OWE (Opportunistic Wireless Encryption). OWE is a standard that provides encryption for open networks without requiring any authentication or credentials from the client or the network. OWE uses a Diffie-Hellman key exchange mechanism to establish a secure session between the client and the AP without exchanging any authentication information. The other options are incorrect because they either describe scenarios that require authentication or encryption methods that are not used by OWE. References:
https://www.arubanetworks.com/assets/wp/WP_WiFi6.pdf https://www.arubanetworks.com/assets/ds/DS_AP510Series.pdf

CoA (Change of Authorization) is a feature that allows ClearPass to dynamically change the authorization and access privileges of a device after it has been authenticated1. CoA uses RADIUS messages to communicate with the network device and instruct it to perform an action, such as reauthenticating the device, applying a new VLAN or user role, or disconnecting the device2.
To enable CoA on a CX switch, the network engineer needs to configure dynamic authorization on the switch, which is a global command that allows the switch to accept RADIUS messages from ClearPass and execute the requested actions3. The network engineer also needs to specify the IP address and shared secret of ClearPass as a dynamic authorization client on the switch3.
To trigger CoA for a specific wired device, the network engineer needs to bounce the switchport, which is an action that temporarily disables and re-enables the port where the device is connected. This forces the device to reauthenticate and receive the new policy from ClearPass. Bouncing the switchport can be done manually by using the interface shutdown and no shutdown commands, or automatically by using ClearPass as a CoA server and sending a RADIUS message with the Port-Bounce-Host AVP (Attribute-Value Pair).

An inbound ACL is applied to traffic entering a port or VLAN. An outbound ACL is applied to traffic leaving a port or VLAN4. To deny ping sourcing from the user VLAN to the IT management VLAN, an inbound ACL on the user VLAN should be used to filter icmp echo traffic toward the IT management VLAN. Icmp echo-reply traffic is not needed to be allowed because it is already permitted by default5. References:
4 https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-9B8F6E8F-9C7A-4F0D-AE7B-9D8E6C5B6A7F.html
5 https://techhub.hpe.com/eginfolib/Aruba/OS-CX_10.04/5200-6692/GUID-0C3A9D0F-6E5B-4E1A-AF3C-8D8B2F9C1A7B.html