Explanation
To correct the issue of not being designated as an integrated Marketing Cloud user, the admin should apply the administrator and Marketing Cloud Administrator permission sets to the user5. The administrator permission set grants the user access to all standard objects and settings in Sales Cloud, while the Marketing Cloud Administrator permission set grants the user access to Marketing Cloud Connect features and settings in Sales Cloud. These permission sets are required for completing the integration between Sales Cloud and Marketing Cloud. The other options are incorrect because:
Apply the Marketing Cloud for AppExchange User option as well. This option will not correct the issue, as it only grants the user access to Marketing Cloud Connect features in Marketing Cloud, not in Sales Cloud. The user also needs access to Marketing Cloud Connect features in Sales Cloud to complete the integration5.
Reset all passwords to force new tokens. This option will not correct the issue, as it only affects the authentication tokens for API users, not for integrated users. The user needs to be designated as an integrated user before they can use their credentials to log in to Marketing Cloud from Sales Cloud5.
Apply the appropriate user mappings in the CRM configuration. This option will not correct the issue, as it only affects how users are mapped between Sales Cloud and Marketing Cloud based on their email addresses or usernames. The user needs to be designated as an integrated user before they can be mapped between the two systems5.