In a model-driven app, a company has a form with the customer`s full address information. The company wants only the sales team to see the customer’s phone number on a form. The company invites you to help design the security of the address information. 
What would you implement to secure the phone number from all users except the sales team?

Answer options:

A.Business unit
B.Field level security
C.Security profile
D.Security role
E.Azure AD group

Correct Answer: B 
Dataverse provides column (field) security level on a column-by-column basis for all custom and most system columns. 
Column-level security gives users more granularity. You need to be cautious about using this feature because it has a global scope. The field will be visible on the app`s screen and marked as secured with the stars for the field value and a lock sign on the field`s side. And it would return the null value in your app.
As a Solution Architect, you advise enabling Column (Field) security for the phone column. You can do this from the Power Apps portal by selecting the Phone number column in the Table browser. Then on the column properties panel (Number 1), you check the "Enable column security" (Number 2) in the Advanced options section.

After that, only the admin and members of a Field Security Profile can see the column value. For management simplification, the Dataverse groups the secured column (field) permissions into a profile. A system administrator can grant access to the profiles to specific users or teams. You can create a Field security profile, add the Sales team as a member, and set the "Allow Read" to "Yes." Now only sales team’s members (and admin) can view the phone number on the app`s form. 
All other options are incorrect. 
For more information about Dataverse Field Security and Profiles, please visit the below URLs: 

https://docs.microsoft.com/en-us/power-platform/admin/wp-security-cds#field-level-security-in-dataverse
https://docs.microsoft.com/en-us/power-platform/admin/field-level-security
https://docs.microsoft.com/en-us/power-platform/admin/add-teams-users-field-security-profile