User Restrictions and Limitations

C.

The correct answer is A. Field-level security & page layouts.

When running a report in Salesforce, users may not be able to include certain fields in the report if those fields have been restricted by the organization's field-level security settings or the user's page layout settings.

Field-level security refers to the ability to restrict access to individual fields on an object, based on user profiles or permission sets. If a user's profile or permission set does not have permission to view a particular field, that field will not be available for inclusion in a report.

Page layouts are used to control the layout and organization of fields on an object's record detail page. If a field has been removed from a user's page layout, that field will not be available for selection when running a report.

It's worth noting that while both field-level security and page layouts can prevent users from including fields in reports, they do so in different ways. Field-level security restricts access to individual fields, while page layouts control the overall organization of fields on a page.