Explanation

SAML -> Connects the client to Workspace ONE Access
Certificate Authority -> Issues certificates for vrm and Enrollment Server Connection Server -> Connects vrm to Active Directory Enrollment Server -> Connects Workspace ONE Access to vrm You can find more information about the Simple True 5SO Architecture in the VMware Horizon 8.x Professional source documents or study guide1. This architecture is a simplified version of the True SSO Architecture, which allows users to log in to their virtual desktops and applications without entering credentials multiple times. The Simple True 5SO Architecture uses Workspace ONE Access as the identity provider, which authenticates users with SAML and issues SAML assertions. The Enrollment Server then uses the SAML assertions to request short-lived certificates from the Certificate Authority, which are used to authenticate users to the Connection Server. The Connection Server then connects users to their virtual desktops and applications through vrm, which is integrated with Active Directory2.
References:
VMware Horizon 8.x Professional
Simple True SSO Architecture

Explanation
VMware App Volumes is a real-time application delivery system that allows administrators to assign applications to users and groups in Horizon. App Volumes uses virtual disks called packages to store and deliver applications. When a user logs on to a desktop, the App Volumes agent attaches the assigned packages to the desktop and merges them with the OS disk. The user can then access the applications as if they were natively installed.
App Volumes is a suitable solution for deploying an application to specific users in an instant-clone desktop environment with the following characteristics:
The application needs to be updated very frequently: App Volumes allows administrators to update applications in real time by using the update or push-image operations. These operations replace the existing packages with new ones that have the latest updates applied, without affecting the user data or settings. The updated packages are delivered to the users at the next login or refresh.
The application needs to be installed as soon as possible: App Volumes allows administrators to install applications quickly and easily by using a clean packaging system and capturing the application installation process. The resulting package can be assigned to users or groups immediately, without requiring any recomposing or rebooting of the desktops.
The application is not multi-user aware: App Volumes allows administrators to deliver applications that are not multi-user aware by using writable volumes. Writable volumesare user-specific virtual disks that store user-installed applications, data, and settings. Writable volumes can be attached to desktops along with application packages, and they can isolate the user-installed applications from the system-installed applications.
The other options are not suitable for meeting the requirements:
VMware Horizon Published Application: This option allows administrators to publish applications from RDS hosts to users in Horizon. However, this option requires a separate RDS infrastructure and licensing, and it does not support instant updates or writable volumes for user-installed applications.
VMware Dynamic Environment Manager: This option allows administrators to manage user profiles and policies in Horizon. However, this option does not deliver or update applications, and it does not support writable volumes for user-installed applications.
VMware ThinApp: This option allows administrators to package applications into portable executables that can run on any Windows system without installation. However, this option requires a separate packaging process and licensing, and it does not support instant updates or writable volumes for user-installed applications.
References: App Volumes Architecture, Updating Applications in Real Time, Writable Volumes Overview, and [VMware Horizon 8.x Professional Course]

Explanation
Collaboration is a feature that allows users to invite other users to join an existing Windows or Linux remote desktop session with both screen sharing and audio out features enabled. A remote desktop session that is shared in this way is called a collaborative session. The user that shares a session with another user is called the session owner, and the user that joins a shared session is called a session collaborator. A Horizon administrator must enable the Session Collaboration feature for the desktop pool or farm that contains the remote desktops that support collaboration.
One of the requirements to enable Session Collaboration is to use the VMware Blast display protocol for the remote desktops. VMware Blast is a protocol that provides high-performance, high-quality graphics and multimedia delivery over LAN or WAN networks. VMware Blast supports Session Collaboration by allowing multiple users to view and interact with the same remote desktop session simultaneously. Other display protocols, such as PCoIP or RDP, do not support Session Collaboration and will not allow users to share or join collaborative sessions.
Therefore, to enable Session Collaboration in the VMware Horizon environment, the administrator needs to use the BLAST protocol as arequirement. References: Configuring Session Collaboration, Sharing Remote Desktop Sessions, and [VMware Horizon 8.x Professional Course]