The customer service department in your company needs to send the messages to AVD users, disconnect the sessions, and sign the users out of the session host. Which role is needed for the customer service department?

Answer options:

A.Session Host Operator
B.User session operator
C.Desktop Virtualization Host Pool Reader
D.Desktop Virtualization Application Group Reader

Correct Answer: B 
The User Session Operator role allows to send the messages to the intended users, disconnect the sessions, and utilize the "logoff" function to sign users out of the session host.
The following figure describes the permissions associated with the User Session Operator role: 

Option A is incorrect.The session Host operator role allows the user to view and remove the session hosts, even changing drain mode.
Option B is correct. The User Session Operator role allows sending the messages to the intended users, disconnecting the sessions, and utilizing the "logoff" function to sign users out of the session host.
Option C is incorrect. Host Pool Reader will allow the user to see everything in the host pool and therefore is not the right role to be assigned.
Option D is incorrect. Application Group Reader should be assigned if you want the user to get access to information about the various applications in the workspace.
Reference: 
To know more about Built-in roles for Azure Virtual Desktop, please visit the below-given link: 

https://docs.microsoft.com/en-us/azure/virtual-desktop/rbac?WT.mc_id=AZ-MVP-5004159