Explanation:

Marketing Cloud Account Engagement provides four standard roles: Administrator, Marketing, Sales Manager, and Sales. "Sales User" is not a defined standard role. The correct role is simply "Sales." Standard roles dictate what functionality users can access, from full admin rights to limited access for viewing leads. Mislabeling roles can lead to confusion in assigning permissions. Therefore, D is correct because “Sales User” does not exist as a standard designation. Proper role assignment ensures users can access the correct tools for their responsibilities in the platform.