Explanation
MAC Caching is a feature that allows a guest user to bypass the captive portal page after the first authentication based on their MAC address1 MAC Caching can be enabled under the splash page settings in Aruba Cloud Guest2 MAC Caching can improve the user experience and reduce the network overhead by eliminating the need for repeated authentication.

Explanation
a) A device with IP address 10.1.3.7 in a network wants to send the traffic stream to a device with IP address
10.13.4.2 in the other network -> Unicast
b) One/more senders and one/more recipients participate in data transfer traffic -> Multicast c) Sent to all hosts on a remote network -> IP Directed Broadcast d) Sent to all NICs on the same network segment as the source NIC -> Broadcast References: 1 https://www.thestudygenius.com/unicast-broadcast-multicast/ The terms broadcast, IP directed broadcast, multicast, and unicast are different types of communication or data transmission over a network. They differ in how many devices are involved in the communication and how they address the messages. The following table summarizes the characteristics of each term1:
A screenshot of a computer Description automatically generated with medium confidence

Multi-Domain Authentication is the feature that should be enabled to support the requirement that the switch must be able to authenticate a single computer connected through a VoIP phone. Multi-Domain Authentication is a feature that allows an Aruba CX switch to apply different authentication methods and policies to different devices connected to the same port. For example, a VoIP phone and a computer can be connected to the same port using a single cable, but they can be authenticated separately using different credentials and assigned to different VLANs. The other options are incorrect because they either do not support multiple devices on the same port or do not provide authentication. References:
https://www.arubanetworks.com/techdocs/AOS-CX/10.05/HTML/5200-7540/GUID-7D9E9F6E-5C2A-4F7E-BE

The HPE Aruba Networking Network Analytics Engine (NAE) uses a Current State Database as a core component. NAE is built into AOS-CX switches and continuously monitors and analyzes network state. The Current State Database stores the real-time operational state of the switch, which NAE agents query and monitor to detect anomalies, trigger alerts, and perform automated diagnostics.

VPN Concentrator is the device persona that is only available when configuring a Gateway-only group on AOS10 Gateways. A device persona defines the role and functionality of a Gateway in a network. A Gateway-only group is a group that contains only Gateways and no APs. A VPN Concentrator persona enables a Gateway to terminate VPN tunnels from remote APs or clients and provide secure access to corporate resources. The other options are incorrect because they are either not device personas or not exclusive to Gateway-only groups.