Please select all the elements that constitute the Business unit security model.

Answer options:

A.Security roles
B.Position
C.Users
D.Teams
E.Manager

Correct Answers: A, C and D 
The Business unit security model is the basis for the Dataverse security. The model controls access to the data using security roles, teams, and users. By linking all of them together, you are getting a role-based security model. By default, the Organization is a top-level of a business unit hierarchy. Each business unit has a default team. You cannot change or delete the default team. You must assign every user to only one business unit. 
The business unit security model uses security roles to assign them to the users or teams. A team also can consist of users from different business units. Options B is incorrect because Position is a hierarchical security role based on a position field assigned to the user.
Options E is incorrect because the Manager is a hierarchical security role based on the manager field on each user record that specifies the user`s manager.
For more information about Dataverse business units security, please visit the below URLs: 

https://docs.microsoft.com/en-us/power-platform/admin/wp-security-cds
https://docs.microsoft.com/en-us/power-platform/admin/create-edit-business-units
https://www.youtube.com/watch?v=8UWSj-vvxzU