Universal containers uses salesforce knowledge and has defined its category groups based on the regions of europe, of americas, africa, and asia. the administrator needs to restrict visibility of each category to the sales representatives within each region. how should the administrator control access to these category groups? a. add custom category groups to the profiles assigned to the sales users. b. modify object settings for the category groups on the sales users' profiles. c. add custom category groups to the roles assigned to the sales users. d. add or remove sales users from a public group with access to the category groups.